Split Personality of a Potyvirus: To Specialize or Not to Specialize?

PubMed Central

Kehoe, Monica A.; Coutts, Brenda A.; Buirchell, Bevan J.; Jones, Roger A. C.

2014-01-01

Bean yellow mosaic virus (BYMV), genus Potyvirus, has an extensive natural host range encompassing both dicots and monocots. Its phylogenetic groups were considered to consist of an ancestral generalist group and six specialist groups derived from this generalist group during plant domestication. Recombination was suggested to be playing a role in BYMV's evolution towards host specialization. However, in subsequent phylogenetic analysis of whole genomes, group names based on the original hosts of isolates within each of them were no longer supported. Also, nine groups were found and designated I-IX. Recombination analysis was conducted on the complete coding regions of 33 BYMV genomes and two genomes of the related Clover yellow vein virus (CYVV). This analysis found evidence for 12 firm recombination events within BYMV phylogenetic groups I–VI, but none within groups VII–IX or CYVV. The greatest numbers of recombination events within a sequence (two or three each) occurred in four groups, three which formerly constituted the single ancestral generalist group (I, II and IV), and group VI. The individual sequences in groups III and V had one event each. These findings with whole genomes are consistent with recombination being associated with expanding host ranges, and call into question the proposed role of recombination in the evolution of BYMV, where it was previously suggested to play a role in host specialization. Instead, they (i) indicate that recombination explains the very broad natural host ranges of the three BYMV groups which infect both monocots and dicots (I, II, IV), and (ii) suggest that the three groups with narrow natural host ranges (III, V, VI) which also showed recombination now have the potential to reduce host specificity and broaden their natural host ranges. PMID:25148372

Current status of Tomato chlorotic spot virus in Florida and the Caribbean

USDA-ARS?s Scientific Manuscript database

Damaging outbreaks of Tomato chlorotic spot virus (TCSV), an emerging thrips-vectored tospovirus, and several invasive species of thrips are significantly impacting vegetable and other crops in Florida and the Caribbean. Host and geographic ranges of TCSV are continuing to expand in this region. Dev...

Rapidly expanding genetic diversity and host range of the Circoviridae viral family and other Rep encoding small circular ssDNA genomes

PubMed Central

Delwart, Eric; Li, Linlin

2011-01-01

The genomes of numerous circoviruses and distantly related circular DNA viruses encoding a rolling circle replication initiator protein (Rep) have been characterized from the tissues of mammals, fish, insects, and plants (geminivirus and nanovirus), human and animal feces, in an algae cell, and in diverse environmental samples. We review the genome organization, phylogenetic relationships and initial prevalence studies of cycloviruses, a proposed new genus in the Circoviridae family. Viral fossil rep sequences were also identified integrated on the chromosomes of mammals, frogs, lancelets, crustaceans, mites, gastropods, roundworms, placozoans, hydrozoans, protozoans, land plants, fungi, algae, and phytoplasma bacterias and their plasmids, reflecting their past host range. An ancient origin for viruses with rep-encoding single stranded small circular genomes, predating the diversification of eukaryotes, is discussed. The cellular hosts and pathogenicity of many recently described rep-containing circular genomes remain to be determined. Future studies of the virome of single cell and multi-cellular eukaryotes are likely to further extend the known diversity and host-range of small rep-containing circular viral genomes. PMID:22155583

The role of belowground plant-microbe interactions in climate change induced range shifts

NASA Astrophysics Data System (ADS)

Ramirez, Kelly; Snoek, Basten; van der Putten, Wim

2017-04-01

With climate change, plants have been able to shift their ranges into novel environments were conditions have been made suitable due to warming temperature and changes in precipitation. Much belowground range expansion research has focused on either positive plant-soil interactions, such as AMF symbiosis, or on negative plant-soil interactions, such as pathogens. Less focus has been given to the core microbiome of plant hosts. Many unknowns remain in how the soil microbiome may contribute to plant adaptation to climate change, and how this may feedback to plant-soil interactions and ecosystem functions. Using high-throughput Illumina sequencing we assessed soil and root microbial communities under native and range expanding plant species spanning a north-south latitudinal transect in central Europe. As expected, the soil and root microbiomes are both strongly influenced by the plant species under which they grow. Specifically, about 10% of the microbiome could be related to the host plant species. Interestingly, we found that microbiomes associated with range shifting species are less variable than those associated with native species. Further, the enrichment of microbes in roots (from the soil) is stronger with range expanding species than with native plant species. Our research indicates that the soil and root microbiomes can provide insight into plant range shifts and may be important for plant establishment. Our results are also important at a continental and global level, as ecosystems and plant communities worldwide are effected by climate change induced range-expansions.

Host and parasite thermal ecology jointly determine the effect of climate warming on epidemic dynamics.

PubMed

Gehman, Alyssa-Lois M; Hall, Richard J; Byers, James E

2018-01-23

Host-parasite systems have intricately coupled life cycles, but each interactor can respond differently to changes in environmental variables like temperature. Although vital to predicting how parasitism will respond to climate change, thermal responses of both host and parasite in key traits affecting infection dynamics have rarely been quantified. Through temperature-controlled experiments on an ectothermic host-parasite system, we demonstrate an offset in the thermal optima for survival of infected and uninfected hosts and parasite production. We combine experimentally derived thermal performance curves with field data on seasonal host abundance and parasite prevalence to parameterize an epidemiological model and forecast the dynamical responses to plausible future climate-warming scenarios. In warming scenarios within the coastal southeastern United States, the model predicts sharp declines in parasite prevalence, with local parasite extinction occurring with as little as 2 °C warming. The northern portion of the parasite's current range could experience local increases in transmission, but assuming no thermal adaptation of the parasite, we find no evidence that the parasite will expand its range northward under warming. This work exemplifies that some host populations may experience reduced parasitism in a warming world and highlights the need to measure host and parasite thermal performance to predict infection responses to climate change.

Special feature: alien pests threatening biodiversity of forest ecosystems. Editorial.

Treesearch

Naoto Kamata; Kurt W. Gottschalk

2007-01-01

Throughout the world, biological invasions have become one of the most important factors threatening biodiversity. Many species are introduced into "a new world" accidentally or intentionally. Most fail to become established, but some become established, colonize, and start to increase and expand their ranges. Some invasive pathogens damage and kill host...

Vision-mediated exploitation of a novel host plant by a tephritid fruit fly.

PubMed

Piñero, Jaime C; Souder, Steven K; Vargas, Roger I

2017-01-01

Shortly after its introduction into the Hawaiian Islands around 1895, the polyphagous, invasive fruit fly Bactrocera (Zeugodacus) cucurbitae (Coquillett) (Diptera: Tephritidae) was provided the opportunity to expand its host range to include a novel host, papaya (Carica papaya). It has been documented that female B. cucurbitae rely strongly on vision to locate host fruit. Given that the papaya fruit is visually conspicuous in the papaya agro-ecosystem, we hypothesized that female B. cucurbitae used vision as the main sensory modality to find and exploit the novel host fruit. Using a comparative approach that involved a series of studies under natural and semi-natural conditions in Hawaii, we assessed the ability of female B. cucurbitae to locate and oviposit in papaya fruit using the sensory modalities of olfaction and vision alone and also in combination. The results of these studies demonstrate that, under a variety of conditions, volatiles emitted by the novel host do not positively stimulate the behavior of the herbivore. Rather, vision seems to be the main mechanism driving the exploitation of the novel host. Volatiles emitted by the novel host papaya fruit did not contribute in any way to the visual response of females. Our findings highlight the remarkable role of vision in the host-location process of B. cucurbitae and provide empirical evidence for this sensory modality as a potential mechanism involved in host range expansion.

Vision-mediated exploitation of a novel host plant by a tephritid fruit fly

PubMed Central

2017-01-01

Shortly after its introduction into the Hawaiian Islands around 1895, the polyphagous, invasive fruit fly Bactrocera (Zeugodacus) cucurbitae (Coquillett) (Diptera: Tephritidae) was provided the opportunity to expand its host range to include a novel host, papaya (Carica papaya). It has been documented that female B. cucurbitae rely strongly on vision to locate host fruit. Given that the papaya fruit is visually conspicuous in the papaya agro-ecosystem, we hypothesized that female B. cucurbitae used vision as the main sensory modality to find and exploit the novel host fruit. Using a comparative approach that involved a series of studies under natural and semi-natural conditions in Hawaii, we assessed the ability of female B. cucurbitae to locate and oviposit in papaya fruit using the sensory modalities of olfaction and vision alone and also in combination. The results of these studies demonstrate that, under a variety of conditions, volatiles emitted by the novel host do not positively stimulate the behavior of the herbivore. Rather, vision seems to be the main mechanism driving the exploitation of the novel host. Volatiles emitted by the novel host papaya fruit did not contribute in any way to the visual response of females. Our findings highlight the remarkable role of vision in the host-location process of B. cucurbitae and provide empirical evidence for this sensory modality as a potential mechanism involved in host range expansion. PMID:28380069

Phylogenetic relatedness and host plant growth form influence gene expression of the polyphagous comma butterfly (Polygonia c-album)

PubMed Central

Heidel-Fischer, Hanna M; Freitak, Dalial; Janz, Niklas; Söderlind, Lina; Vogel, Heiko; Nylin, Sören

2009-01-01

Background The mechanisms that shape the host plant range of herbivorous insect are to date not well understood but knowledge of these mechanisms and the selective forces that influence them can expand our understanding of the larger ecological interaction. Nevertheless, it is well established that chemical defenses of plants influence the host range of herbivorous insects. While host plant chemistry is influenced by phylogeny, also the growth forms of plants appear to influence the plant defense strategies as first postulated by Feeny (the "plant apparency" hypothesis). In the present study we aim to investigate the molecular basis of the diverse host plant range of the comma butterfly (Polygonia c-album) by testing differential gene expression in the caterpillars on three host plants that are either closely related or share the same growth form. Results In total 120 genes were identified to be differentially expressed in P. c-album after feeding on different host plants, 55 of them in the midgut and 65 in the restbody of the caterpillars. Expression patterns could be confirmed with an independent method for 14 of 27 tested genes. Pairwise similarities in upregulation in the midgut of the caterpillars were higher between plants that shared either growth form or were phylogenetically related. No known detoxifying enzymes were found to be differently regulated in the midgut after feeding on different host plants. Conclusion Our data suggest a complex picture of gene expression in response to host plant feeding. While each plant requires a unique gene regulation in the caterpillar, both phylogenetic relatedness and host plant growth form appear to influence the expression profile of the polyphagous comma butterfly, in agreement with phylogenetic studies of host plant utilization in butterflies. PMID:19878603

Phylogenetic relatedness and host plant growth form influence gene expression of the polyphagous comma butterfly (Polygonia c-album).

PubMed

Heidel-Fischer, Hanna M; Freitak, Dalial; Janz, Niklas; Söderlind, Lina; Vogel, Heiko; Nylin, Sören

2009-10-31

The mechanisms that shape the host plant range of herbivorous insect are to date not well understood but knowledge of these mechanisms and the selective forces that influence them can expand our understanding of the larger ecological interaction. Nevertheless, it is well established that chemical defenses of plants influence the host range of herbivorous insects. While host plant chemistry is influenced by phylogeny, also the growth forms of plants appear to influence the plant defense strategies as first postulated by Feeny (the "plant apparency" hypothesis). In the present study we aim to investigate the molecular basis of the diverse host plant range of the comma butterfly (Polygonia c-album) by testing differential gene expression in the caterpillars on three host plants that are either closely related or share the same growth form. In total 120 genes were identified to be differentially expressed in P. c-album after feeding on different host plants, 55 of them in the midgut and 65 in the restbody of the caterpillars. Expression patterns could be confirmed with an independent method for 14 of 27 tested genes. Pairwise similarities in upregulation in the midgut of the caterpillars were higher between plants that shared either growth form or were phylogenetically related. No known detoxifying enzymes were found to be differently regulated in the midgut after feeding on different host plants. Our data suggest a complex picture of gene expression in response to host plant feeding. While each plant requires a unique gene regulation in the caterpillar, both phylogenetic relatedness and host plant growth form appear to influence the expression profile of the polyphagous comma butterfly, in agreement with phylogenetic studies of host plant utilization in butterflies.

Hybridization between two cestode species and its consequences for intermediate host range

PubMed Central

2013-01-01

Background Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F1 hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii), both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively). Methods We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. Results We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Conclusions Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations. PMID:23390985

Rapidly expanding genetic diversity and host range of the Circoviridae viral family and other Rep encoding small circular ssDNA genomes.

PubMed

Delwart, Eric; Li, Linlin

2012-03-01

The genomes of numerous circoviruses and distantly related circular ssDNA viruses encoding a rolling circle replication initiator protein (Rep) have been characterized from the tissues of mammals, fish, insects, plants (geminivirus and nanovirus), in human and animal feces, in an algae cell, and in diverse environmental samples. We review the genome organization, phylogenetic relationships and initial prevalence studies of cycloviruses, a proposed new genus in the Circoviridae family. Viral fossil rep sequences were also recently identified integrated on the chromosomes of mammals, frogs, lancelets, crustaceans, mites, gastropods, roundworms, placozoans, hydrozoans, protozoans, land plants, fungi, algae, and phytoplasma bacterias and their plasmids, reflecting the very wide past host range of rep bearing viruses. An ancient origin for viruses with Rep-encoding small circular ssDNA genomes, predating the diversification of eukaryotes, is discussed. The cellular hosts and pathogenicity of many recently described rep-containing circular ssDNA genomes remain to be determined. Future studies of the virome of single cell and multi-cellular eukaryotes are likely to further extend the known diversity and host-range of small rep-containing circular ssDNA viral genomes. Copyright © 2011 Elsevier B.V. All rights reserved.

New host record and molecular characterization of Dicauda atherinoidi Hoffman & Walker (Bivalvulida: Myxobolidae): a parasite of the emerald shiner Notropis atherinoides Rafinesque, 1818 and mimic shiner Notropis vollucellus Cope, 1865.

PubMed

Loch, T P; Rosser, T G; Baumgartner, W A; Boontai, T; Faisal, M; Griffin, M J

2017-10-01

Updated morphological and histopathological descriptions for Dicauda atherinoidi (Bivalvulida:Myxobolidae) and an expanded host range are supplemented with the first molecular data and phylogenetic analyses of the genus. Plasmodia were located on the head, ventrum/body and fins of infected emerald shiner Notropis atherinoides Rafinesque, 1818 and mimic shiner Notropis vollucellus Cope, 1865, a new host species. Myxospores were spherical, ranging 9.3-11.4 μm (10.5 ± 0.4) in length, 9.0-11.0 μm (9.7 ± 0.4) in width and 6.6-7.0 μm (6.8 ± 0.2) thick in sutural view, and possessed 2-3 caudal processes (5.3-68.3 μm, 31.1 ± 13.6) connected to the spore body at the sutural groove, all of which are consistent with the genus Dicauda. In the absence of available Dicauda sequence data, the 18S rDNA sequences from Michigan isolates were most similar to Myxobolus spp. Phylogenetic analyses clustered these isolates with myxobolid species from cyprinid fish, suggesting these parasites may represent an underpopulated group of cyprinid-infecting myxozoans. Histopathology revealed thin-walled plasmodial pseudocysts in the dermis and associated connective tissue, where granulomatous inflammation and focal scale atrophy were also present. Further sampling/sequencing of myxobolids from Notropis spp. should expand these underrepresented myxozoans and offer further insight into Myxobolidae host family tropisms. © 2017 John Wiley & Sons Ltd.

Spatial relationship between Phytophthora ramorum and roads or streams in Oregon tanoak forests

Treesearch

Ebba Peterson; Everett Hansen; Alan Kanaskie

2014-01-01

The pathogen, Phytophthora ramorum, causal agent of sudden oak death (SOD) of oaks and tanoaks, continues to expand its range within Oregon despite an effort to eradicate it from native forests. With its early detection and prompt removal of infected hosts, the Oregon SOD eradication program has produced a landscape distribution of disease...

The Trw Type IV Secretion System of Bartonella Mediates Host-Specific Adhesion to Erythrocytes

PubMed Central

Vayssier-Taussat, Muriel; Le Rhun, Danielle; Deng, Hong Kuan; Biville, Francis; Cescau, Sandra; Danchin, Antoine; Marignac, Geneviève; Lenaour, Evelyne; Boulouis, Henri Jean; Mavris, Maria; Arnaud, Lionel; Yang, Huanming; Wang, Jing; Quebatte, Maxime; Engel, Philipp; Saenz, Henri; Dehio, Christoph

2010-01-01

Bacterial pathogens typically infect only a limited range of hosts; however, the genetic mechanisms governing host-specificity are poorly understood. The α-proteobacterial genus Bartonella comprises 21 species that cause host-specific intraerythrocytic bacteremia as hallmark of infection in their respective mammalian reservoirs, including the human-specific pathogens Bartonella quintana and Bartonella bacilliformis that cause trench fever and Oroya fever, respectively. Here, we have identified bacterial factors that mediate host-specific erythrocyte colonization in the mammalian reservoirs. Using mouse-specific Bartonella birtlesii, human-specific Bartonella quintana, cat-specific Bartonella henselae and rat-specific Bartonella tribocorum, we established in vitro adhesion and invasion assays with isolated erythrocytes that fully reproduce the host-specificity of erythrocyte infection as observed in vivo. By signature-tagged mutagenesis of B. birtlesii and mutant selection in a mouse infection model we identified mutants impaired in establishing intraerythrocytic bacteremia. Among 45 abacteremic mutants, five failed to adhere to and invade mouse erythrocytes in vitro. The corresponding genes encode components of the type IV secretion system (T4SS) Trw, demonstrating that this virulence factor laterally acquired by the Bartonella lineage is directly involved in adherence to erythrocytes. Strikingly, ectopic expression of Trw of rat-specific B. tribocorum in cat-specific B. henselae or human-specific B. quintana expanded their host range for erythrocyte infection to rat, demonstrating that Trw mediates host-specific erythrocyte infection. A molecular evolutionary analysis of the trw locus further indicated that the variable, surface-located TrwL and TrwJ might represent the T4SS components that determine host-specificity of erythrocyte parasitism. In conclusion, we show that the laterally acquired Trw T4SS diversified in the Bartonella lineage to facilitate host-restricted adhesion to erythrocytes in a wide range of mammals. PMID:20548954

Colonization behaviors of mountain pine beetle on novel hosts: Implications for range expansion into northeastern North America

PubMed Central

Venette, Robert C.; Maddox, Mitchell P.; Aukema, Brian H.

2017-01-01

As climates change, thermal limits may no longer constrain some native herbivores within their historical ranges. The mountain pine beetle, Dendroctonus ponderosae Hopkins, is a tree-killing bark beetle native to western North America that is currently expanding its range. Continued eastward expansion through the newly invaded and novel jack pine (Pinus banksiana Lamb.) trees of the Canadian boreal forest could result in exposure of several species of novel potential host pines common in northeastern North America to this oligophagous herbivore. Due to the tightly co-evolved relationship between mountain pine beetle and western pine hosts, in which the insect utilizes the defensive chemistry of the host to stimulate mass attacks, we hypothesized that lack of co-evolutionary association would affect the host attraction and acceptance behaviors of this insect among novel hosts, particularly those with little known historical association with an aggressive stem-infesting insect. We studied how beetle behavior differed among the various stages of colonization on newly cut logs of four novel potential pine host species; jack, red (P. resinosa Ait.), eastern white (P. strobus L.) and Scots (P. sylvestris L.) pines, as well as two historical hosts, ponderosa (P. ponderosa Dougl. ex. Laws. var. scopulorum Engelm.) and lodgepole (P. contorta Dougl. var. latifolia Engelm.) pines. Overall, we found that beetle colonization behaviors at each stage in the colonization process differ between pine hosts, likely due to differing chemical and physical bark traits. Pines without co-evolved constitutive defenses against mountain pine beetle exhibited reduced amounts of defensive monoterpenoid chemicals; however, such patterns also reduced beetle attraction and colonization. Neither chemical nor physical defenses fully defended trees against the various stages of host procurement that can result in tree colonization and death. PMID:28472047

Colonization behaviors of mountain pine beetle on novel hosts: Implications for range expansion into northeastern North America.

PubMed

Rosenberger, Derek W; Venette, Robert C; Maddox, Mitchell P; Aukema, Brian H

2017-01-01

As climates change, thermal limits may no longer constrain some native herbivores within their historical ranges. The mountain pine beetle, Dendroctonus ponderosae Hopkins, is a tree-killing bark beetle native to western North America that is currently expanding its range. Continued eastward expansion through the newly invaded and novel jack pine (Pinus banksiana Lamb.) trees of the Canadian boreal forest could result in exposure of several species of novel potential host pines common in northeastern North America to this oligophagous herbivore. Due to the tightly co-evolved relationship between mountain pine beetle and western pine hosts, in which the insect utilizes the defensive chemistry of the host to stimulate mass attacks, we hypothesized that lack of co-evolutionary association would affect the host attraction and acceptance behaviors of this insect among novel hosts, particularly those with little known historical association with an aggressive stem-infesting insect. We studied how beetle behavior differed among the various stages of colonization on newly cut logs of four novel potential pine host species; jack, red (P. resinosa Ait.), eastern white (P. strobus L.) and Scots (P. sylvestris L.) pines, as well as two historical hosts, ponderosa (P. ponderosa Dougl. ex. Laws. var. scopulorum Engelm.) and lodgepole (P. contorta Dougl. var. latifolia Engelm.) pines. Overall, we found that beetle colonization behaviors at each stage in the colonization process differ between pine hosts, likely due to differing chemical and physical bark traits. Pines without co-evolved constitutive defenses against mountain pine beetle exhibited reduced amounts of defensive monoterpenoid chemicals; however, such patterns also reduced beetle attraction and colonization. Neither chemical nor physical defenses fully defended trees against the various stages of host procurement that can result in tree colonization and death.

Divergent Viruses Discovered in Arthropods and Vertebrates Revise the Evolutionary History of the Flaviviridae and Related Viruses.

PubMed

Shi, Mang; Lin, Xian-Dan; Vasilakis, Nikos; Tian, Jun-Hua; Li, Ci-Xiu; Chen, Liang-Jun; Eastwood, Gillian; Diao, Xiu-Nian; Chen, Ming-Hui; Chen, Xiao; Qin, Xin-Cheng; Widen, Steven G; Wood, Thomas G; Tesh, Robert B; Xu, Jianguo; Holmes, Edward C; Zhang, Yong-Zhen

2016-01-15

Viruses of the family Flaviviridae are important pathogens of humans and other animals and are currently classified into four genera. To better understand their diversity, evolutionary history, and genomic flexibility, we used transcriptome sequencing (RNA-seq) to search for the viruses related to the Flaviviridae in a range of potential invertebrate and vertebrate hosts. Accordingly, we recovered the full genomes of five segmented jingmenviruses and 12 distant relatives of the known Flaviviridae ("flavi-like" viruses) from a range of arthropod species. Although these viruses are highly divergent, they share a similar genomic plan and common ancestry with the Flaviviridae in the NS3 and NS5 regions. Remarkably, although these viruses fill in major gaps in the phylogenetic diversity of the Flaviviridae, genomic comparisons reveal important changes in genome structure, genome size, and replication/gene regulation strategy during evolutionary history. In addition, the wide diversity of flavi-like viruses found in invertebrates, as well as their deep phylogenetic positions, suggests that they may represent the ancestral forms from which the vertebrate-infecting viruses evolved. For the vertebrate viruses, we expanded the previously mammal-only pegivirus-hepacivirus group to include a virus from the graceful catshark (Proscyllium habereri), which in turn implies that these viruses possess a larger host range than is currently known. In sum, our data show that the Flaviviridae infect a far wider range of hosts and exhibit greater diversity in genome structure than previously anticipated. The family Flaviviridae of RNA viruses contains several notorious human pathogens, including dengue virus, West Nile virus, and hepatitis C virus. To date, however, our understanding of the biodiversity and evolution of the Flaviviridae has largely been directed toward vertebrate hosts and their blood-feeding arthropod vectors. Therefore, we investigated an expanded group of potential arthropod and vertebrate host species that have generally been ignored by surveillance programs. Remarkably, these species contained diverse flaviviruses and related viruses that are characterized by major changes in genome size and genome structure, such that these traits are more flexible than previously thought. More generally, these data suggest that arthropods may be the ultimate reservoir of the Flaviviridae and related viruses, harboring considerable genetic and phenotypic diversity. In sum, this study revises the traditional view on the evolutionary history, host range, and genomic structures of a major group of RNA viruses. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

An illustrated key to Neotropical species of the genus Meteorus Haliday (Hymenoptera, Braconidae, Euphorinae).

PubMed

Aguirre, Helmuth; de Almeida, Luis Felipe; Shaw, Scott Richard; Sarmiento, Carlos E

2015-01-01

A comprehensive key for 75 species of Meteorus distributed across 15 Neotropical countries is presented. Eleven new species from Bolivia, Costa Rica and Ecuador are described: Meteorusalbistigma, Meteoruscarolae, Meteoruseurysaccavorus, Meteorusfallacavus, Meteorusflavistigma, Meteorushaimowitzi, Meteorusmagnoculus, Meteorusmartinezi, Meteorusmicrocavus, Meteorusnoctuivorus and Meteorusorion. Expanded range distributions are recorded for Meteorusandreae, Meteorusfarallonensis, Meteorusguineverae, Meteorusjerodi, Meteoruskraussi, Meteoruspapiliovorus and Meteorusquimbayensis. The host of Meteorusjerodi is reported for the first time: a noctuid larva feeding on Asteraceae. Meteoruspapiliovorus is recorded attacking Papilionidae larvae in Ecuador, therefore displaying a similar host family preference as formerly documented from Costa Rica and Colombia.

Isolation and Characterization of Mycoplasma sphenisci sp. nov. from the Choana of an Aquarium-Reared Jackass Penguin (Spheniscus demersus)

PubMed Central

Frasca, Salvatore; Weber, E. Scott; Urquhart, Heather; Liao, Xiaofen; Gladd, Martha; Cecchini, Katharine; Hudson, Paul; May, Meghan; Gast, Rebecca J.; Gorton, Timothy S.; Geary, Steven J.

2005-01-01

Strain UCMJ was isolated from the choana of a jackass penguin (Spheniscus demersus) with recurrent mucocaseous choanal discharge. Isolation of this mycoplasma expands the known range of species hosting mycoplasmas. The name Mycoplasma sphenisci sp. nov. is proposed for this new species, for which strain UCMJ is the type strain. PMID:15956436

Some like it hot: evolution and ecology of novel endosymbionts in bat flies of cave-roosting bats (hippoboscoidea, nycterophiliinae).

PubMed

Morse, Solon F; Dick, Carl W; Patterson, Bruce D; Dittmar, Katharina

2012-12-01

We investigated previously unknown associations between bacterial endosymbionts and bat flies of the subfamily Nycterophiliinae (Diptera, Streblidae). Molecular analyses revealed a novel clade of Gammaproteobacteria in Nycterophilia bat flies. This clade was not closely related to Arsenophonus-like microbes found in its sister genus Phalconomus and other bat flies. High population infection rates in Nycterophilia across a wide geographic area, the presence of the symbionts in pupae, the general codivergence between hosts and symbionts, and high AT composition bias in symbiont genes together suggest that this host-symbiont association is obligate in nature and ancient in origin. Some Nycterophilia samples (14.8%) also contained Wolbachia supergroup F (Alphaproteobacteria), suggesting a facultative symbiosis. Likelihood-based ancestral character mapping revealed that, initially, obligate symbionts exhibited association with host-specific Nycterophilia bat flies that use a broad temperature range of cave environments for pupal development. As this mutualism evolved, the temperature range of bat flies narrowed to an exclusive use of hot caves, which was followed by a secondary broadening of the bat flies' host associations. These results suggest that the symbiosis has influenced the environmental tolerance of parasite life history stages. Furthermore, the contingent change to an expanded host range of Nycterophilia bat flies upon narrowing the ecological niche of their developmental stages suggests that altered environmental tolerance across life history stages may be a crucial factor in shaping parasite-host relationships.

Some Like It Hot: Evolution and Ecology of Novel Endosymbionts in Bat Flies of Cave-Roosting Bats (Hippoboscoidea, Nycterophiliinae)

PubMed Central

Morse, Solon F.; Dick, Carl W.; Patterson, Bruce D.

2012-01-01

We investigated previously unknown associations between bacterial endosymbionts and bat flies of the subfamily Nycterophiliinae (Diptera, Streblidae). Molecular analyses revealed a novel clade of Gammaproteobacteria in Nycterophilia bat flies. This clade was not closely related to Arsenophonus-like microbes found in its sister genus Phalconomus and other bat flies. High population infection rates in Nycterophilia across a wide geographic area, the presence of the symbionts in pupae, the general codivergence between hosts and symbionts, and high AT composition bias in symbiont genes together suggest that this host-symbiont association is obligate in nature and ancient in origin. Some Nycterophilia samples (14.8%) also contained Wolbachia supergroup F (Alphaproteobacteria), suggesting a facultative symbiosis. Likelihood-based ancestral character mapping revealed that, initially, obligate symbionts exhibited association with host-specific Nycterophilia bat flies that use a broad temperature range of cave environments for pupal development. As this mutualism evolved, the temperature range of bat flies narrowed to an exclusive use of hot caves, which was followed by a secondary broadening of the bat flies' host associations. These results suggest that the symbiosis has influenced the environmental tolerance of parasite life history stages. Furthermore, the contingent change to an expanded host range of Nycterophilia bat flies upon narrowing the ecological niche of their developmental stages suggests that altered environmental tolerance across life history stages may be a crucial factor in shaping parasite-host relationships. PMID:23042170

Mesenchymal stromal cell supported umbilical cord blood ex vivo expansion enhances regulatory T cells and reduces graft versus host disease.

PubMed

Fan, Xiubo; Gay, Florence Pik Hoon; Ong, Shin-Yeu; Ang, Justina May Lynn; Chu, Pat Pak Yan; Bari, Sudipto; Lim, Tony Kiat Hon; Hwang, William Ying Khee

2013-05-01

Double cord blood transplantation (DCBT) may shorten neutrophil and platelet recovery times compared with standard umbilical cord blood transplantation. However, DCBT may be associated with a higher incidence of graft versus host disease (GVHD). In this study, we explored the effect of ex vivo expansion of a single cord blood unit (CBU) in a DCBT setting on GVHD and engraftment. Post-thaw cryopreserved CBUs from cord blood banks, hereinafter termed "banked" CBUs, were co-cultured with confluent bone marrow mesenchymal stromal cells (MSCs) supplemented with a cytokine cocktail comprising 100 ng/mL stem cell factor, 50 ng/mL flt3-ligand, 100 ng/mL thrombopoietin and 20 ng/mL insulin-like growth factor binding protein 2 for 12 days. When DCBT of one unexpanded and one expanded CBU was performed in non-obese diabetic/severe combined immunodeficient-IL2Rgamma(null) (NOD/SCID-IL2γ(-/-), NSG) mice, the expanded CBU significantly boosted in vivo hematopoiesis of the unexpanded CBU. The median survival of NSG mice was significantly improved from 63.4% (range, 60.0-66.7%) for mice receiving only unexpanded units to 86.5% (range, 80.0-92.9%) for mice receiving an expanded unit (P < 0.001). The difference in survival appeared to be due to a lower incidence of GVHD in the mice receiving expanded cells. This effect on GVHD was mediated by a significant increase in regulatory T cells seen in the presence of MSC co-culture. MSC-supported ex vivo expansion of "banked" CBU boosted unexpanded CBU hematopoiesis in vivo, increased regulatory T cell content and decreased the incidence of GVHD. Copyright © 2013. Published by Elsevier Inc.

Life history and biology of Fascioloides magna (Trematoda) and its native and exotic hosts

PubMed Central

Malcicka, Miriama

2015-01-01

Host–parasite interactions are model systems in a wide range of ecological and evolutionary fields and may be utilized for testing numerous theories and hypotheses in terms of both applied and fundamental research. For instance, they are important in terms of studying coevolutionary arms races, species invasions, and in economic terms the health of livestock and humans. Here, I present a comprehensive description of the life history, biogeography, and biology of the giant liver fluke, Fascioloides magna, and both its intermediate and definitive hosts. F. magna is native to North America where it uses several species of freshwater snails (Lymnaeidae) as intermediate hosts and four main species of ungulates as definitive hosts. The fluke has also been introduced into parts of Europe where it is now established in two lymnaeid snail species and three ungulate species. This study gives a comprehensive description of different developmental stages of the fluke in its two host classes, as well as detailed notes on historical and present distributions of F. magna in North America and Europe as well as in its snail and deer hosts (with range maps provided). Aberrant and dead-end hosts are also discussed in detail, and descriptive phylogenies are provided for all of the organisms. I briefly discuss how F. magna represents a model example of multiple-level ecological fitting, a phenomenon not yet described in the empirical literature. Lastly, I explore possible future scenarios for fluke invasion in Europe, where it is currently expanding its range. PMID:25897378

Strategic removal of host trees in isolated, satellite infestations of emerald ash borer can reduce population growth

Treesearch

Samuel J. Fahrner; Mark Abrahamson; Robert C. Venette; Brian H. Aukema

2017-01-01

Emerald ash borer is an invasive beetle causing significant mortality of ash trees (Fraxinus spp.) in North America and western Russia. The invasive range has expanded to more than half of the states in the United States since the initial detection in Michigan, USA in 2002. Emerald ash borer is typically managed with a combination of techniques...

Genome-Wide RNAi Screen Identifies Broadly-Acting Host Factors That Inhibit Arbovirus Infection

PubMed Central

Yasunaga, Ari; Hanna, Sheri L.; Li, Jianqing; Cho, Hyelim; Rose, Patrick P.; Spiridigliozzi, Anna; Gold, Beth; Diamond, Michael S.; Cherry, Sara

2014-01-01

Vector-borne viruses are an important class of emerging and re-emerging pathogens; thus, an improved understanding of the cellular factors that modulate infection in their respective vertebrate and insect hosts may aid control efforts. In particular, cell-intrinsic antiviral pathways restrict vector-borne viruses including the type I interferon response in vertebrates and the RNA interference (RNAi) pathway in insects. However, it is likely that additional cell-intrinsic mechanisms exist to limit these viruses. Since insects rely on innate immune mechanisms to inhibit virus infections, we used Drosophila as a model insect to identify cellular factors that restrict West Nile virus (WNV), a flavivirus with a broad and expanding geographical host range. Our genome-wide RNAi screen identified 50 genes that inhibited WNV infection. Further screening revealed that 17 of these genes were antiviral against additional flaviviruses, and seven of these were antiviral against other vector-borne viruses, expanding our knowledge of invertebrate cell-intrinsic immunity. Investigation of two newly identified factors that restrict diverse viruses, dXPO1 and dRUVBL1, in the Tip60 complex, demonstrated they contributed to antiviral defense at the organismal level in adult flies, in mosquito cells, and in mammalian cells. These data suggest the existence of broadly acting and functionally conserved antiviral genes and pathways that restrict virus infections in evolutionarily divergent hosts. PMID:24550726

Flavivirus structural heterogeneity: implications for cell entry.

PubMed

Rey, Félix A; Stiasny, Karin; Heinz, Franz X

2017-06-01

The explosive spread of Zika virus is the most recent example of the threat imposed to human health by flaviviruses. High-resolution structures are available for several of these arthropod-borne viruses, revealing alternative icosahedral organizations of immature and mature virions. Incomplete proteolytic maturation, however, results in a cloud of highly heterogeneous mosaic particles. This heterogeneity is further expanded by a dynamic behavior of the viral envelope glycoproteins. The ensemble of heterogeneous and dynamic infectious particles circulating in infected hosts offers a range of alternative possible receptor interaction sites at their surfaces, potentially contributing to the broad flavivirus host-range and variation in tissue tropism. The potential synergy between heterogeneous particles in the circulating cloud thus provides an additional dimension to understand the unanticipated properties of Zika virus in its recent outbreaks. Copyright © 2017 Elsevier B.V. All rights reserved.

50-plus years of fungal viruses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghabrial, Said A., E-mail: saghab00@email.uky.edu; Castón, José R.; Jiang, Daohong

2015-05-15

Mycoviruses are widespread in all major taxa of fungi. They are transmitted intracellularly during cell division, sporogenesis, and/or cell-to-cell fusion (hyphal anastomosis), and thus their life cycles generally lack an extracellular phase. Their natural host ranges are limited to individuals within the same or closely related vegetative compatibility groups, although recent advances have established expanded experimental host ranges for some mycoviruses. Most known mycoviruses have dsRNA genomes packaged in isometric particles, but an increasing number of positive- or negative-strand ssRNA and ssDNA viruses have been isolated and characterized. Although many mycoviruses do not have marked effects on their hosts, thosemore » that reduce the virulence of their phytopathogenic fungal hosts are of considerable interest for development of novel biocontrol strategies. Mycoviruses that infect endophytic fungi and those that encode killer toxins are also of special interest. Structural analyses of mycoviruses have promoted better understanding of virus assembly, function, and evolution. - Highlights: • Historical perspective of fungal virus research. • Description, classification and diversity of fungal virus families. • Structural features of fungal virus particles. • Hypovirulence and exploitation of mycoviruses in biological control of plant pathogenic fungi.« less

Plant nodulation inducers enhance horizontal gene transfer of Azorhizobium caulinodans symbiosis island

PubMed Central

Ling, Jun; Wang, Hui; Wu, Ping; Li, Tao; Tang, Yu; Naseer, Nawar; Zheng, Huiming; Masson-Boivin, Catherine; Zhong, Zengtao

2016-01-01

Horizontal gene transfer (HGT) of genomic islands is a driving force of bacterial evolution. Many pathogens and symbionts use this mechanism to spread mobile genetic elements that carry genes important for interaction with their eukaryotic hosts. However, the role of the host in this process remains unclear. Here, we show that plant compounds inducing the nodulation process in the rhizobium-legume mutualistic symbiosis also enhance the transfer of symbiosis islands. We demonstrate that the symbiosis island of the Sesbania rostrata symbiont, Azorhizobium caulinodans, is an 87.6-kb integrative and conjugative element (ICEAc) that is able to excise, form a circular DNA, and conjugatively transfer to a specific site of gly-tRNA gene of other rhizobial genera, expanding their host range. The HGT frequency was significantly increased in the rhizosphere. An ICEAc-located LysR-family transcriptional regulatory protein AhaR triggered the HGT process in response to plant flavonoids that induce the expression of nodulation genes through another LysR-type protein, NodD. Our study suggests that rhizobia may sense rhizosphere environments and transfer their symbiosis gene contents to other genera of rhizobia, thereby broadening rhizobial host-range specificity. PMID:27849579

Plant nodulation inducers enhance horizontal gene transfer of Azorhizobium caulinodans symbiosis island.

PubMed

Ling, Jun; Wang, Hui; Wu, Ping; Li, Tao; Tang, Yu; Naseer, Nawar; Zheng, Huiming; Masson-Boivin, Catherine; Zhong, Zengtao; Zhu, Jun

2016-11-29

Horizontal gene transfer (HGT) of genomic islands is a driving force of bacterial evolution. Many pathogens and symbionts use this mechanism to spread mobile genetic elements that carry genes important for interaction with their eukaryotic hosts. However, the role of the host in this process remains unclear. Here, we show that plant compounds inducing the nodulation process in the rhizobium-legume mutualistic symbiosis also enhance the transfer of symbiosis islands. We demonstrate that the symbiosis island of the Sesbania rostrata symbiont, Azorhizobium caulinodans, is an 87.6-kb integrative and conjugative element (ICE Ac ) that is able to excise, form a circular DNA, and conjugatively transfer to a specific site of gly-tRNA gene of other rhizobial genera, expanding their host range. The HGT frequency was significantly increased in the rhizosphere. An ICE Ac -located LysR-family transcriptional regulatory protein AhaR triggered the HGT process in response to plant flavonoids that induce the expression of nodulation genes through another LysR-type protein, NodD. Our study suggests that rhizobia may sense rhizosphere environments and transfer their symbiosis gene contents to other genera of rhizobia, thereby broadening rhizobial host-range specificity.

Disentangling Detoxification: Gene Expression Analysis of Feeding Mountain Pine Beetle Illuminates Molecular-Level Host Chemical Defense Detoxification Mechanisms

PubMed Central

Robert, Jeanne A.; Pitt, Caitlin; Bonnett, Tiffany R.; Yuen, Macaire M. S.; Keeling, Christopher I.; Bohlmann, Jörg; Huber, Dezene P. W.

2013-01-01

The mountain pine beetle, Dendroctonus ponderosae, is a native species of bark beetle (Coleoptera: Curculionidae) that caused unprecedented damage to the pine forests of British Columbia and other parts of western North America and is currently expanding its range into the boreal forests of central and eastern Canada and the USA. We conducted a large-scale gene expression analysis (RNA-seq) of mountain pine beetle male and female adults either starved or fed in male-female pairs for 24 hours on lodgepole pine host tree tissues. Our aim was to uncover transcripts involved in coniferophagous mountain pine beetle detoxification systems during early host colonization. Transcripts of members from several gene families significantly increased in insects fed on host tissue including: cytochromes P450, glucosyl transferases and glutathione S-transferases, esterases, and one ABC transporter. Other significantly increasing transcripts with potential roles in detoxification of host defenses included alcohol dehydrogenases and a group of unexpected transcripts whose products may play an, as yet, undiscovered role in host colonization by mountain pine beetle. PMID:24223726

Disentangling detoxification: gene expression analysis of feeding mountain pine beetle illuminates molecular-level host chemical defense detoxification mechanisms.

PubMed

Robert, Jeanne A; Pitt, Caitlin; Bonnett, Tiffany R; Yuen, Macaire M S; Keeling, Christopher I; Bohlmann, Jörg; Huber, Dezene P W

2013-01-01

The mountain pine beetle, Dendroctonus ponderosae, is a native species of bark beetle (Coleoptera: Curculionidae) that caused unprecedented damage to the pine forests of British Columbia and other parts of western North America and is currently expanding its range into the boreal forests of central and eastern Canada and the USA. We conducted a large-scale gene expression analysis (RNA-seq) of mountain pine beetle male and female adults either starved or fed in male-female pairs for 24 hours on lodgepole pine host tree tissues. Our aim was to uncover transcripts involved in coniferophagous mountain pine beetle detoxification systems during early host colonization. Transcripts of members from several gene families significantly increased in insects fed on host tissue including: cytochromes P450, glucosyl transferases and glutathione S-transferases, esterases, and one ABC transporter. Other significantly increasing transcripts with potential roles in detoxification of host defenses included alcohol dehydrogenases and a group of unexpected transcripts whose products may play an, as yet, undiscovered role in host colonization by mountain pine beetle.

Platelet-lysate-expanded mesenchymal stromal cells as a salvage therapy for severe resistant graft-versus-host disease in a pediatric population.

PubMed

Lucchini, Giovanna; Introna, Martino; Dander, Erica; Rovelli, Attilio; Balduzzi, Adriana; Bonanomi, Sonia; Salvadè, Agnese; Capelli, Chiara; Belotti, Daniela; Gaipa, Giuseppe; Perseghin, Paolo; Vinci, Paola; Lanino, Edoardo; Chiusolo, Patrizia; Orofino, Maria Grazia; Marktel, Sarah; Golay, Jose; Rambaldi, Alessandro; Biondi, Andrea; D'Amico, Giovanna; Biagi, Ettore

2010-09-01

Despite advances in graft-versus-host-disease (GVHD) treatment, it is estimated that overall survival (OS) at 2 years for hematopoietic cell transplantation (HCT) recipients who experience steroid-resistant GVHD is 10%. Among recent therapeutic approaches for GVHD treatment, mesenchymal stromal cells (MSCs) hold a key position. We describe a multicenter experience of 11 pediatric patients diagnosed with acute or chronic GVHD (aGVHD, cGVHD) treated for compassionate use with GMP-grade unrelated HLA-disparate donors' bone marrow-derived MSCs, expanded in platelet-lysate (PL)-containing medium. Eleven patients (aged 4-15 years) received intravenous (i.v.) MSCs for aGVHD or cGVHD, which was resistant to multiple lines of immunosuppression. The median dose was 1.2 x 10(6)/kg (range: 0.7-3.7 x 10(6)/kg). No acute side effects were observed, and no late side effects were reported at a median follow-up of 8 months (range: 4-18 months). Overall response was obtained in 71.4% of patients, with complete response in 23.8% of cases. None of our patients presented GVHD progression upon MSC administration, but 4 patients presented GVHD recurrence 2 to 5 months after infusion. Two patients developed chronic limited GVHD. This study underlines the safety of PL-expanded MSC use in children. MSC efficacy seems to be greater in aGVHD than in cGVHD, even after failure of multiple lines of immunosuppression. Copyright (c) 2010 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Dynamics and management of infectious disease in colonizing populations.

PubMed

Bar-David, Shirli; Lloyd-Smith, James O; Getz, Wayne M

2006-05-01

The introduction of chronic, infectious diseases by colonizing populations (invasive or reintroduced) is a serious hazard in conservation biology, threatening the original host and other spillover species. Most research on spatial invasion of diseases has pertained to established host populations, either at steady state or fluctuating through time. Within a colonizing population, however, the spread of disease may be influenced by the expansion process of the population itself. Here we explore the simultaneous expansion of a colonizing population and a chronic, nonlethal disease introduced with it, describing basic patterns in homogeneous and structured landscapes and discussing implications for disease management. We describe expected outcomes of such introductions for three qualitatively distinct cases, depending on the relative velocities at which the population and epidemic expand. (1) If transmissibility is low the disease cannot be sustained, although it may first expand its range somewhat around the point of introduction. (2) If transmissibility is moderate but the wave-front velocity for the population, vp, is higher than that for the disease, vd, the disease wave front lags behind that of the population. (3) A highly transmissible disease, with vd > vp, will invade sufficiently rapidly to track the spread of the host. To test these elementary theoretical predictions, we simulated disease outbreaks in a spatially structured host population occupying a real landscape. We used a spatially explicit, individual-based model of Persian fallow deer (Dama mesopotamica) reintroduced in northern Israel, considering a hypothetical introduction of bovine tuberculosis. Basic patterns of disease expansion in this realistic setting were similar to our conceptual predictions for homogeneous landscapes. Landscape heterogeneity, however, induced the establishment of population activity centers and disease foci within them, leading to jagged wave fronts and causing local variation in the relative velocities at which the population and epidemic expanded. Based on predictions from simple theory and simulations of managed outbreaks, we suggest that the relative velocities at which the population and epidemic expand have important implications for the impact of different management strategies. Recognizing which of our three general cases best describes a particular outbreak will aid in planning an efficient strategy to contain the disease.

Heritable symbiosis: The advantages and perils of an evolutionary rabbit hole.

PubMed

Bennett, Gordon M; Moran, Nancy A

2015-08-18

Many eukaryotes have obligate associations with microorganisms that are transmitted directly between generations. A model for heritable symbiosis is the association of aphids, a clade of sap-feeding insects, and Buchnera aphidicola, a gammaproteobacterium that colonized an aphid ancestor 150 million years ago and persists in almost all 5,000 aphid species. Symbiont acquisition enables evolutionary and ecological expansion; aphids are one of many insect groups that would not exist without heritable symbiosis. Receiving less attention are potential negative ramifications of symbiotic alliances. In the short run, symbionts impose metabolic costs. Over evolutionary time, hosts evolve dependence beyond the original benefits of the symbiosis. Symbiotic partners enter into an evolutionary spiral that leads to irreversible codependence and associated risks. Host adaptations to symbiosis (e.g., immune-system modification) may impose vulnerabilities. Symbiont genomes also continuously accumulate deleterious mutations, limiting their beneficial contributions and environmental tolerance. Finally, the fitness interests of obligate heritable symbionts are distinct from those of their hosts, leading to selfish tendencies. Thus, genes underlying the host-symbiont interface are predicted to follow a coevolutionary arms race, as observed for genes governing host-pathogen interactions. On the macroevolutionary scale, the rapid evolution of interacting symbiont and host genes is predicted to accelerate host speciation rates by generating genetic incompatibilities. However, degeneration of symbiont genomes may ultimately limit the ecological range of host species, potentially increasing extinction risk. Recent results for the aphid-Buchnera symbiosis and related systems illustrate that, whereas heritable symbiosis can expand ecological range and spur diversification, it also presents potential perils.

Expanding the host range of small insect RNA viruses: Providence virus (Carmotetraviridae) infects and replicates in a human tissue culture cell line.

PubMed

Jiwaji, Meesbah; Short, James Roswell; Dorrington, Rosemary Ann

2016-10-01

Tetraviruses are small, positive (+ve)-sense ssRNA viruses that infect the midgut cells of lepidopteran larvae. Providence virus (PrV) is the only member of the family Carmotetraviridae (previously Tetraviridae). PrV particles exhibit the characteristic tetraviral T=4 icosahedral symmetry, but PrV is distinct from other tetraviruses with respect to genome organization and viral non-structural proteins. Currently, PrV is the only tetravirus known to infect and replicate in lepidopteran cell culture lines. In this report we demonstrate, using immunofluorescence microscopy, that PrV infects and replicates in a human tissue culture cell line (HeLa), producing infectious virus particles. We also provide evidence for PrV replication in vitro in insect, mammalian and plant cell-free systems. This study challenges the long-held view that tetraviruses have a narrow host range confined to one or a few lepidopteran species and highlights the need to consider the potential for apparently non-infectious viruses to be transferred to new hosts in the laboratory.

Echinostomes in Felid Coprolites from Brazil.

PubMed

Sianto, L; Duarte, A N; Borba, V H; Magalhães, J G; de Souza, S M; Chame, M

2016-06-01

The first record of Echinostoma (Trematoda: Echinostomatidae) in coprolites was from a mummified human body in Minas Gerais State, Brazil. The finding raised questions on this parasite's incidence in prehistoric populations and the natural hosts of each species in remote times. Echinostomes occur worldwide and, despite the wide range of hosts, there is no record of Echinostomatidae in felines in Brazil. This study reports the finding of Echinostomatidae eggs in felid coprolites in the Furna do Estrago Archaeological Site, located in Pernambuco State in the Brazilian semiarid. Despite the possibility of false parasitism, the finding expands the distribution of this Digenea in remote times and raises the hypothesis of other cases of echinostomiasis in pre-Colombian populations.

Climate change may alter breeding ground distributions of eastern migratory monarchs (Danaus plexippus) via range expansion of Asclepias host plants.

PubMed

Lemoine, Nathan P

2015-01-01

Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months while encountering reduced habitat suitability throughout the northern migration.

Climate Change May Alter Breeding Ground Distributions of Eastern Migratory Monarchs (Danaus plexippus) via Range Expansion of Asclepias Host Plants

PubMed Central

Lemoine, Nathan P.

2015-01-01

Climate change can profoundly alter species’ distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months while encountering reduced habitat suitability throughout the northern migration. PMID:25705876

Mountain pine beetle host selection between lodgepole and ponderosa pines in the southern Rocky Mountains

USGS Publications Warehouse

West, Daniel R.; Briggs, Jenny S.; Jacobi, William R.; Negron, Jose F.

2016-01-01

Recent evidence of range expansion and host transition by mountain pine beetle ( Dendroctonus ponderosae Hopkins; MPB) has suggested that MPB may not primarily breed in their natal host, but will switch hosts to an alternate tree species. As MPB populations expanded in lodgepole pine forests in the southern Rocky Mountains, we investigated the potential for movement into adjacent ponderosa pine forests. We conducted field and laboratory experiments to evaluate four aspects of MPB population dynamics and host selection behavior in the two hosts: emergence timing, sex ratios, host choice, and reproductive success. We found that peak MPB emergence from both hosts occurred simultaneously between late July and early August, and the sex ratio of emerging beetles did not differ between hosts. In two direct tests of MPB host selection, we identified a strong preference by MPB for ponderosa versus lodgepole pine. At field sites, we captured naturally emerging beetles from both natal hosts in choice arenas containing logs of both species. In the laboratory, we offered sections of bark and phloem from both species to individual insects in bioassays. In both tests, insects infested ponderosa over lodgepole pine at a ratio of almost 2:1, regardless of natal host species. Reproductive success (offspring/female) was similar in colonized logs of both hosts. Overall, our findings suggest that MPB may exhibit equally high rates of infestation and fecundity in an alternate host under favorable conditions.

Jack of all trades masters novel host plants: positive genetic correlations in specialist and generalist insect herbivores expanding their diets to novel hosts

PubMed Central

GARCÍA-ROBLEDO, CARLOS; HORVITZ, CAROL C.

2011-01-01

One explanation for the widespread host specialization of insect herbivores is the “Jack of all trades-master of none” principle, which states that genotypes with high performance on one host will perform poorly on other hosts. This principle predicts that cross-host correlation in performance of genotypes will be negative. In this study we experimentally explored cross-host correlations and performance among families in four species (two generalist and two specialist) of leaf beetles (Cephaloleia spp.) that are currently expanding their diets from native to exotic plants. All four species displayed similar responses in body size, developmental rates and mortality rates to experimentally controlled diets. When raised on novel hosts, body size of larvae, pupae and adults were reduced. Development times were longer and larval mortality was higher on novel hosts. Genotype × host plant interactions were not detected for most traits. All significant cross-host correlations were positive. These results indicate very different ecological and evolutionary dynamics than those predicted by the “Jack of all trades-master of none” principle. PMID:22022877

Evolution and Biogeography of Haemonchus contortus: Linking Faunal Dynamics in Space and Time.

PubMed

Hoberg, E P; Zarlenga, D S

2016-01-01

History is the foundation that informs about the nuances of faunal assembly that are essential in understanding the dynamic nature of the host-parasite interface. All of our knowledge begins and ends with evolution, ecology and biogeography, as these interacting facets determine the history of biodiverse systems. These components, relating to Haemonchus, can inform about the complex history of geographical distribution, host association and the intricacies of host-parasite associations that are played out in physiological and behavioural processes that influence the potential for disease and our capacity for effective control in a rapidly changing world. Origins and evolutionary diversification among species of the genus Haemonchus and Haemonchus contortus occurred in a complex crucible defined by shifts in environmental structure emerging from cycles of climate change and ecological perturbation during the late Tertiary and through the Quaternary. A history of sequential host colonization associated with waves of dispersal bringing assemblages of ungulates from Eurasia into Africa and processes emerging from ecosystems in collision and faunal turnover defined the arena for radiation among 12 recognized species of Haemonchus. Among congeners, the host range for H. contortus is exceptionally broad, including species among artiodactyls of 40 genera representing 5 families (and within 12 tribes of Bovidae). Broad host range is dramatically reflected in the degree to which translocation, introduction and invasion with host switching, has characterized an expanding distribution over time in North America, South America, southern Eurasia, Australia and New Zealand, coincidental with agriculture, husbandry and global colonization by human populations driven particularly by European exploration after the 1500s. African origins in xeric to mesic habitats of the African savannah suggest that historical constraints linked to ecological adaptations (tolerances and developmental thresholds defined by temperature and humidity for larval stages) will be substantial determinants in the potential outcomes for widespread geographical and host colonization which are predicted to unfold over the coming century. Insights about deeper evolutionary events, ecology and biogeography are critical as understanding history informs us about the possible range of responses in complex systems under new regimes of environmental forcing, especially, in this case, ecological perturbation linked to climate change. A deeper history of perturbation is relevant in understanding contemporary systems that are now strongly structured by events of invasion and colonization. The relaxation of abiotic and biotic controls on the occurrence of H. contortus, coincidental with inception and dissemination of anthelmintic resistance may be synergistic, serving to exacerbate challenges to control parasites or to limit the socioeconomic impacts of infection that can influence food security and availability. Studies of haemonchine nematodes contribute directly to an expanding model about the nature of diversity and the evolutionary trajectories for faunal assembly among complex host-parasite systems across considerable spatial and temporal scales. Copyright © 2016 Elsevier Ltd. All rights reserved.

Variations in foliar monoterpenes across the range of jack pine reveal three widespread chemotypes: implications to host expansion of invasive mountain pine beetle.

PubMed

Taft, Spencer; Najar, Ahmed; Godbout, Julie; Bousquet, Jean; Erbilgin, Nadir

2015-01-01

The secondary compounds of pines (Pinus) can strongly affect the physiology, ecology and behaviors of the bark beetles (Coleoptera: Curculionidae, Scolytinae) that feed on sub-cortical tissues of hosts. Jack pine (Pinus banksiana) has a wide natural distribution range in North America (Canada and USA) and thus variations in its secondary compounds, particularly monoterpenes, could affect the host expansion of invasive mountain pine beetle (Dendroctonus ponderosae), which has recently expanded its range into the novel jack pine boreal forest. We investigated monoterpene composition of 601 jack pine trees from natural and provenance forest stands representing 63 populations from Alberta to the Atlantic coast. Throughout its range, jack pine exhibited three chemotypes characterized by high proportions of α-pinene, β-pinene, or limonene. The frequency with which the α-pinene and β-pinene chemotypes occurred at individual sites was correlated to climatic variables, such as continentality and mean annual precipitation, as were the individual α-pinene and β-pinene concentrations. However, other monoterpenes were generally not correlated to climatic variables or geographic distribution. Finally, while the enantiomeric ratios of β-pinene and limonene remained constant across jack pine's distribution, (-):(+)-α-pinene exhibited two separate trends, thereby delineating two α-pinene phenotypes, both of which occurred across jack pine's range. These significant variations in jack pine monoterpene composition may have cascading effects on the continued eastward spread and success of D. ponderosae in the Canadian boreal forest.

An illustrated key to Neotropical species of the genus Meteorus Haliday (Hymenoptera, Braconidae, Euphorinae)

PubMed Central

Aguirre, Helmuth; de Almeida, Luis Felipe; Shaw, Scott Richard; Sarmiento, Carlos E.

2015-01-01

Abstract A comprehensive key for 75 species of Meteorus distributed across 15 Neotropical countries is presented. Eleven new species from Bolivia, Costa Rica and Ecuador are described: Meteorus albistigma, Meteorus carolae, Meteorus eurysaccavorus, Meteorus fallacavus, Meteorus flavistigma, Meteorus haimowitzi, Meteorus magnoculus, Meteorus martinezi, Meteorus microcavus, Meteorus noctuivorus and Meteorus orion. Expanded range distributions are recorded for Meteorus andreae, Meteorus farallonensis, Meteorus guineverae, Meteorus jerodi, Meteorus kraussi, Meteorus papiliovorus and Meteorus quimbayensis. The host of Meteorus jerodi is reported for the first time: a noctuid larva feeding on Asteraceae. Meteorus papiliovorus is recorded attacking Papilionidae larvae in Ecuador, therefore displaying a similar host family preference as formerly documented from Costa Rica and Colombia. PMID:25878531

Mountain Pine Beetle Host Selection Between Lodgepole and Ponderosa Pines in the Southern Rocky Mountains.

PubMed

West, Daniel R; Briggs, Jennifer S; Jacobi, William R; Negrón, José F

2016-02-01

Recent evidence of range expansion and host transition by mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB) has suggested that MPB may not primarily breed in their natal host, but will switch hosts to an alternate tree species. As MPB populations expanded in lodgepole pine forests in the southern Rocky Mountains, we investigated the potential for movement into adjacent ponderosa pine forests. We conducted field and laboratory experiments to evaluate four aspects of MPB population dynamics and host selection behavior in the two hosts: emergence timing, sex ratios, host choice, and reproductive success. We found that peak MPB emergence from both hosts occurred simultaneously between late July and early August, and the sex ratio of emerging beetles did not differ between hosts. In two direct tests of MPB host selection, we identified a strong preference by MPB for ponderosa versus lodgepole pine. At field sites, we captured naturally emerging beetles from both natal hosts in choice arenas containing logs of both species. In the laboratory, we offered sections of bark and phloem from both species to individual insects in bioassays. In both tests, insects infested ponderosa over lodgepole pine at a ratio of almost 2:1, regardless of natal host species. Reproductive success (offspring/female) was similar in colonized logs of both hosts. Overall, our findings suggest that MPB may exhibit equally high rates of infestation and fecundity in an alternate host under favorable conditions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Poleward expansion of the white-footed mouse (Peromyscus leucopus) under climate change: implications for the spread of lyme disease.

PubMed

Roy-Dufresne, Emilie; Logan, Travis; Simon, Julie A; Chmura, Gail L; Millien, Virginie

2013-01-01

The white-footed mouse (Peromyscus leucopus) is an important reservoir host for Borrelia burgdorferi, the pathogen responsible for Lyme disease, and its distribution is expanding northward. We used an Ecological Niche Factor Analysis to identify the climatic factors associated with the distribution shift of the white-footed mouse over the last 30 years at the northern edge of its range, and modeled its current and potential future (2050) distributions using the platform BIOMOD. A mild and shorter winter is favouring the northern expansion of the white-footed mouse in Québec. With more favorable winter conditions projected by 2050, the distribution range of the white-footed mouse is expected to expand further northward by 3° latitude. We also show that today in southern Québec, the occurrence of B. burgdorferi is associated with high probability of presence of the white-footed mouse. Changes in the distribution of the white-footed mouse will likely alter the geographical range of B. burgdorferi and impact the public health in northern regions that have yet to be exposed to Lyme disease.

Heritable symbiosis: The advantages and perils of an evolutionary rabbit hole

PubMed Central

Bennett, Gordon M.; Moran, Nancy A.

2015-01-01

Many eukaryotes have obligate associations with microorganisms that are transmitted directly between generations. A model for heritable symbiosis is the association of aphids, a clade of sap-feeding insects, and Buchnera aphidicola, a gammaproteobacterium that colonized an aphid ancestor 150 million years ago and persists in almost all 5,000 aphid species. Symbiont acquisition enables evolutionary and ecological expansion; aphids are one of many insect groups that would not exist without heritable symbiosis. Receiving less attention are potential negative ramifications of symbiotic alliances. In the short run, symbionts impose metabolic costs. Over evolutionary time, hosts evolve dependence beyond the original benefits of the symbiosis. Symbiotic partners enter into an evolutionary spiral that leads to irreversible codependence and associated risks. Host adaptations to symbiosis (e.g., immune-system modification) may impose vulnerabilities. Symbiont genomes also continuously accumulate deleterious mutations, limiting their beneficial contributions and environmental tolerance. Finally, the fitness interests of obligate heritable symbionts are distinct from those of their hosts, leading to selfish tendencies. Thus, genes underlying the host–symbiont interface are predicted to follow a coevolutionary arms race, as observed for genes governing host–pathogen interactions. On the macroevolutionary scale, the rapid evolution of interacting symbiont and host genes is predicted to accelerate host speciation rates by generating genetic incompatibilities. However, degeneration of symbiont genomes may ultimately limit the ecological range of host species, potentially increasing extinction risk. Recent results for the aphid–Buchnera symbiosis and related systems illustrate that, whereas heritable symbiosis can expand ecological range and spur diversification, it also presents potential perils. PMID:25713367

Strategic targeting of essential host-pathogen interactions in chlamydial disease.

PubMed

Coombes, B K; Johnson, D L; Mahony, J B

2002-09-01

The chlamydiae are obligate intracellular gram-negative bacteria that are exquisitely adapted for exploitation of their hosts and contribute to a wide range of acute and chronic human diseases. Acute infections treated with non-cidal antibiotics can lead to the development of persistent, non-replicating bacteria with the corollary that these persistent (yet viable) chlamydiae can resist eradication by further antimicrobial treatment and cause chronic disease. These findings highlight an urgent need for therapeutics that are effective against persistent infections and call for creative approaches to identify potential drug targets. The C. pneumoniae and C. trachomatis genome projects have greatly expanded our knowledge of chlamydial pathogenesis and have provided an enormous potential for the identification and characterization of unknown genes and potential virulence factors in these bacteria. As intracellular pathogens, chlamydiae rely on host cells for all aspects of their survival, from the initial attachment with host cell membranes, to cellular invasion, acquisition of host cell metabolites and intracellular replication. As such, the molecules participating in interactions with the host could be attractive targets for therapeutic intervention. This review describes recent advances in chlamydial genomics, proteomics and cell biology that have cast light on host-pathogen relations that are essential for chlamydial survival. Using this knowledge, we discuss how strategically interfering with essential interactions between chlamydiae and the host cell could be exploited to develop an innovative, and potentially more relevant arsenal of therapeutic compounds.

An Anthropocentric View of the Virosphere-Host Relationship

PubMed Central

Rodrigues, Rodrigo A. L.; Andrade, Ana C. dos S. P.; Boratto, Paulo V. de M.; Trindade, Giliane de S.; Kroon, Erna G.; Abrahão, Jônatas S.

2017-01-01

For over a century, viruses have been known as the most abundant and diverse group of organisms on Earth, forming a virosphere. Based on extensive meta-analyses, we present, for the first time, a wide and complete overview of virus–host network, covering all known viral species. Our data indicate that most of known viral species, regardless of their genomic category, have an intriguingly narrow host range, infecting only 1 or 2 host species. Our data also show that the known virosphere has expanded based on viruses of human interest, related to economical, medical or biotechnological activities. In addition, we provide an overview of the distribution of viruses on different environments on Earth, based on meta-analyses of available metaviromic data, showing the contrasting ubiquity of head-tailed phages against the specificity of some viral groups in certain environments. Finally, we uncovered all human viral species, exploring their diversity and the most affected organic systems. The virus–host network presented here shows an anthropocentric view of the virology. It is therefore clear that a huge effort and change in perspective is necessary to see more than the tip of the iceberg when it comes to virology. PMID:28912772

Shiny cowbird parasitism in two avian communities in Puerto Rico

USGS Publications Warehouse

Wiley, J.W.

1985-01-01

The shiny cowbird (M. bonariensis), a brood parasite, has recently expanded its range from South America to Puerto Rico via the Lesser Antilles. This species is a host generalist and, on reaching Puerto Rico, encounteed avian species with no history of social parasitism. In mangrove habitat study areas, 42% of the resident non-raptorial land bird species were parasitized. Some species were heavily parasitized; e.g., yellow warbler (Dendroica petechia), 76% of nests parasitized black-whiskered vireo (Vireo altiloquus), 82%, Puerto Rican flycatcher (Myiarchus antillarum), 85%, yellow-shouldered blackbird (Agelaius xanthomus), 95%, troupial (Icterus icterus), 100%, black-cowled oriole (I. dominicensis), 100%. Others suffered low rates of parasitism (2-17% of nests examined); e.g., gray kingbird (Tyrannus dominicensis), red-legged thrush (Turdus plumbeus), bronze mannikin (Lonchura cucullata), northern mockingbird (Mimus polyglottos), greater antillean grackle (Quiscalus niger). Cowbird parasitism affected hosts by depressing nest success an average of 41% below non-parasitized nests and reducing host productivity. Parasitized host nests hatched 12% fewer eggs an fledged 67% fewer of their own chicks than non-parasitized pairs.

Origin and invasion of the emerging infectious pathogen Sphaerothecum destruens

PubMed Central

Sana, Salma; Hardouin, Emilie A; Gozlan, Rodolphe E; Ercan, Didem; Tarkan, Ali Serhan; Zhang, Tiantian; Andreou, Demetra

2017-01-01

Non-native species are often linked to the introduction of novel pathogens with detrimental effects on native biodiversity. Since Sphaerothecum destruens was first discovered as a fish pathogen in the United Kingdom, it has been identified as a potential threat to European fish biodiversity. Despite this parasite’s emergence and associated disease risk, there is still a poor understanding of its origin in Europe. Here, we provide the first evidence to support the hypothesis that S. destruens was accidentally introduced to Europe from China along with its reservoir host Pseudorasbora parva via the aquaculture trade. This is the first study to confirm the presence of S. destruens in China, and it has expanded the confirmed range of S. destruens to additional locations in Europe. The demographic analysis of S. destruens and its host P. parva in their native and invasive range further supported the close association of both species. This research has direct significance and management implications for S. destruens in Europe as a non-native parasite. PMID:28831194

Origins, evolution, and diversification of cleptoparasitic lineages in long-tongued bees.

PubMed

Litman, Jessica R; Praz, Christophe J; Danforth, Bryan N; Griswold, Terry L; Cardinal, Sophie

2013-10-01

The evolution of parasitic behavior may catalyze the exploitation of new ecological niches yet also binds the fate of a parasite to that of its host. It is thus not clear whether evolutionary transitions from free-living organism to parasite lead to increased or decreased rates of diversification. We explore the evolution of brood parasitism in long-tongued bees and find decreased rates of diversification in eight of 10 brood parasitic clades. We propose a pathway for the evolution of brood parasitic strategy and find that a strategy in which a closed host nest cell is parasitized and the host offspring is killed by the adult parasite represents an obligate first step in the appearance of a brood parasitic lineage; this ultimately evolves into a strategy in which an open host cell is parasitized and the host offspring is killed by a specialized larval instar. The transition to parasitizing open nest cells expanded the range of potential hosts for brood parasitic bees and played a fundamental role in the patterns of diversification seen in brood parasitic clades. We address the prevalence of brood parasitic lineages in certain families of bees and examine the evolution of brood parasitism in other groups of organisms. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

A Proposal for a Genome Similarity-Based Taxonomy for Plant-Pathogenic Bacteria that Is Sufficiently Precise to Reflect Phylogeny, Host Range, and Outbreak Affiliation Applied to Pseudomonas syringae sensu lato as a Proof of Concept.

PubMed

Vinatzer, Boris A; Weisberg, Alexandra J; Monteil, Caroline L; Elmarakeby, Haitham A; Sheppard, Samuel K; Heath, Lenwood S

2017-01-01

Taxonomy of plant pathogenic bacteria is challenging because pathogens of different crops often belong to the same named species but current taxonomy does not provide names for bacteria below the subspecies level. The introduction of the host range-based pathovar system in the 1980s provided a temporary solution to this problem but has many limitations. The affordability of genome sequencing now provides the opportunity for developing a new genome-based taxonomic framework. We already proposed to name individual bacterial isolates based on pairwise genome similarity. Here, we expand on this idea and propose to use genome similarity-based codes, which we now call life identification numbers (LINs), to describe and name bacterial taxa. Using 93 genomes of Pseudomonas syringae sensu lato, LINs were compared with a P. syringae genome tree whereby the assigned LINs were found to be informative of a majority of phylogenetic relationships. LINs also reflected host range and outbreak association for strains of P. syringae pathovar actinidiae, a pathovar for which many genome sequences are available. We conclude that LINs could provide the basis for a new taxonomic framework to address the shortcomings of the current pathovar system and to complement the current taxonomic system of bacteria in general.

Large-scale determinants of intestinal schistosomiasis and intermediate host snail distribution across Africa: does climate matter?

PubMed

Stensgaard, Anna-Sofie; Utzinger, Jürg; Vounatsou, Penelope; Hürlimann, Eveline; Schur, Nadine; Saarnak, Christopher F L; Simoonga, Christopher; Mubita, Patricia; Kabatereine, Narcis B; Tchuem Tchuenté, Louis-Albert; Rahbek, Carsten; Kristensen, Thomas K

2013-11-01

The geographical ranges of most species, including many infectious disease agents and their vectors and intermediate hosts, are assumed to be constrained by climatic tolerances, mainly temperature. It has been suggested that global warming will cause an expansion of the areas potentially suitable for infectious disease transmission. However, the transmission of infectious diseases is governed by a myriad of ecological, economic, evolutionary and social factors. Hence, a deeper understanding of the total disease system (pathogens, vectors and hosts) and its drivers is important for predicting responses to climate change. Here, we combine a growing degree day model for Schistosoma mansoni with species distribution models for the intermediate host snail (Biomphalaria spp.) to investigate large-scale environmental determinants of the distribution of the African S. mansoni-Biomphalaria system and potential impacts of climatic changes. Snail species distribution models included several combinations of climatic and habitat-related predictors; the latter divided into "natural" and "human-impacted" habitat variables to measure anthropogenic influence. The predictive performance of the combined snail-parasite model was evaluated against a comprehensive compilation of historical S. mansoni parasitological survey records, and then examined for two climate change scenarios of increasing severity for 2080. Future projections indicate that while the potential S. mansoni transmission area expands, the snail ranges are more likely to contract and/or move into cooler areas in the south and east. Importantly, we also note that even though climate per se matters, the impact of humans on habitat play a crucial role in determining the distribution of the intermediate host snails in Africa. Thus, a future contraction in the geographical range size of the intermediate host snails caused by climatic changes does not necessarily translate into a decrease or zero-sum change in human schistosomiasis prevalence. Copyright © 2011 Elsevier B.V. All rights reserved.

Avian influenza virus, Streptococcus suis serotype 2, severe acute respiratory syndrome-coronavirus and beyond: molecular epidemiology, ecology and the situation in China.

PubMed

Ma, Ying; Feng, Youjun; Liu, Di; Gao, George F

2009-09-27

The outbreak and spread of severe acute respiratory syndrome-associated coronavirus and the subsequent identification of its animal origin study have heightened the world's awareness of animal-borne or zoonotic pathogens. In addition to SARS, the highly pathogenic avian influenza virus (AIV), H5N1, and the lower pathogenicity H9N2 AIV have expanded their host ranges to infect human beings and other mammalian species as well as birds. Even the 'well-known' reservoir animals for influenza virus, migratory birds, became victims of the highly pathogenic H5N1 virus. Not only the viruses, but bacteria can also expand their host range: a new disease, streptococcal toxic shock syndrome, caused by human Streptococcus suis serotype 2 infection, has been observed in China with 52 human fatalities in two separate outbreaks (1998 and 2005, respectively). Additionally, enterohaemorrhagic Escherichia coli O157:H7 infection has increased worldwide with severe disease. Several outbreaks and sporadic isolations of this pathogen in China have made it an important target for disease control. A new highly pathogenic variant of porcine reproductive and respiratory syndrome virus (PRRSV) has been isolated in both China and Vietnam recently; although PRRSV is not a zoonotic human pathogen, its severe outbreaks have implications for food safety. All of these pathogens occur in Southeast Asia, including China, with severe consequences; therefore, we discuss the issues in this article by addressing the situation of the zoonotic threat in China.

Comparative genomics of parasitic silkworm microsporidia reveal an association between genome expansion and host adaptation

PubMed Central

2013-01-01

Background Microsporidian Nosema bombycis has received much attention because the pébrine disease of domesticated silkworms results in great economic losses in the silkworm industry. So far, no effective treatment could be found for pébrine. Compared to other known Nosema parasites, N. bombycis can unusually parasitize a broad range of hosts. To gain some insights into the underlying genetic mechanism of pathological ability and host range expansion in this parasite, a comparative genomic approach is conducted. The genome of two Nosema parasites, N. bombycis and N. antheraeae (an obligatory parasite to undomesticated silkworms Antheraea pernyi), were sequenced and compared with their distantly related species, N. ceranae (an obligatory parasite to honey bees). Results Our comparative genomics analysis show that the N. bombycis genome has greatly expanded due to the following three molecular mechanisms: 1) the proliferation of host-derived transposable elements, 2) the acquisition of many horizontally transferred genes from bacteria, and 3) the production of abundnant gene duplications. To our knowledge, duplicated genes derived not only from small-scale events (e.g., tandem duplications) but also from large-scale events (e.g., segmental duplications) have never been seen so abundant in any reported microsporidia genomes. Our relative dating analysis further indicated that these duplication events have arisen recently over very short evolutionary time. Furthermore, several duplicated genes involving in the cytotoxic metabolic pathway were found to undergo positive selection, suggestive of the role of duplicated genes on the adaptive evolution of pathogenic ability. Conclusions Genome expansion is rarely considered as the evolutionary outcome acting on those highly reduced and compact parasitic microsporidian genomes. This study, for the first time, demonstrates that the parasitic genomes can expand, instead of shrink, through several common molecular mechanisms such as gene duplication, horizontal gene transfer, and transposable element expansion. We also showed that the duplicated genes can serve as raw materials for evolutionary innovations possibly contributing to the increase of pathologenic ability. Based on our research, we propose that duplicated genes of N. bombycis should be treated as primary targets for treatment designs against pébrine. PMID:23496955

The Strange, Expanding World of Animal Hepaciviruses

PubMed Central

Hartlage, Alex S.; Cullen, John M.; Kapoor, Amit

2017-01-01

Hepaciviruses and pegiviruses constitute two closely related sister genera of the family Flaviviridae. In the past five years, the known phylogenetic diversity of the hepacivirus genera has absolutely exploded. What was once an isolated infection in humans (and possibly other primates) has now expanded to include horses, rodents, bats, colobus monkeys, cows, and, most recently, catsharks, shedding new light on the genetic diversity and host range of hepaciviruses. Interestingly, despite the identification of these many animal and primate hepaciviruses, the equine hepaciviruses remain the closest genetic relatives of the human hepaciviruses, providing an intriguing clue to the zoonotic source of hepatitis C virus. This review summarizes the significance of these studies and discusses current thinking about the origin and evolution of the animal hepaciviruses as well as their potential usage as surrogate models for the study of hepatitis C virus. PMID:27741408

Geographical Assessment of Rickettsioses in Indonesia.

PubMed

Widjaja, Susana; Williams, Maya; Winoto, Imelda; Farzeli, Arik; Stoops, Craig A; Barbara, Kathryn A; Richards, Allen L; Blair, Patrick J

2016-01-01

To expand the documentation of rickettsioses in Indonesia, we conducted an ectoparasite and small mammal investigation involving four major islands: Java, Sumatra, Sulawesi, and Kalimantan. Coastal and highland regions on each island surveyed were chosen to represent different ecologies in Indonesia. Indication of the presence of Rickettsia spp. was evident in all areas sampled. Typhus group rickettsiae-specific antibodies had significantly higher prevalence among small mammals captured in Java compared to the other islands surveyed (78% in coastal and 50% in highland regions) and the prevalence of spotted fever group rickettsiae-specific antibodies was significantly higher in Kalimantan than the other islands investigated. Hosts and vectors were restricted by Rickettsia spp. but not by coastal or highland regions. Our findings expand the range in which rickettsial pathogens have been documented within the Indonesian archipelago and point to a significant risk to human health.

Range-expanding pests and pathogens in a warming world.

PubMed

Bebber, Daniel Patrick

2015-01-01

Crop pests and pathogens (CPPs) present a growing threat to food security and ecosystem management. The interactions between plants and their natural enemies are influenced by environmental conditions and thus global warming and climate change could affect CPP ranges and impact. Observations of changing CPP distributions over the twentieth century suggest that growing agricultural production and trade have been most important in disseminating CPPs, but there is some evidence for a latitudinal bias in range shifts that indicates a global warming signal. Species distribution models using climatic variables as drivers suggest that ranges will shift latitudinally in the future. The rapid spread of the Colorado potato beetle across Eurasia illustrates the importance of evolutionary adaptation, host distribution, and migration patterns in affecting the predictions of climate-based species distribution models. Understanding species range shifts in the framework of ecological niche theory may help to direct future research needs.

Crop domestication facilitated rapid geographical expansion of a specialist pollinator, the squash bee Peponapis pruinosa

PubMed Central

Cane, James H.; Minckley, Robert L.; Danforth, Bryan N.

2016-01-01

Squash was first domesticated in Mexico and is now found throughout North America (NA) along with Peponapis pruinosa, a pollen specialist bee species of the squash genus Cucurbita. The origin and spread of squash cultivation is well-studied archaeologically and phylogenetically; however, no study has documented how cultivation of this or any other crop has influenced species in mutualistic interactions. We used molecular markers to reconstruct the demographic range expansion and colonization routes of P. pruinosa from its native range into temperate NA. Populations east of the Rocky Mountains expanded from the wild host plant's range in Mexico and were established by a series of founder events. Eastern North America was most likely colonized from squash bee populations in the present-day continental Midwest USA and not from routes that followed the Gulf and Atlantic coasts from Mexico. Populations of P. pruinosa west of the Rockies spread north from the warm deserts much more recently, showing two genetically differentiated populations with no admixture: one in California and the other one in eastern Great Basin. These bees have repeatedly endured severe bottlenecks as they colonized NA, following human spread of their Cucurbita pollen hosts during the Holocene. PMID:27335417

Pheromone Production by an Invasive Bark Beetle Varies with Monoterpene Composition of its Naïve Host.

PubMed

Taft, Spencer; Najar, Ahmed; Erbilgin, Nadir

2015-06-01

The secondary chemistry of host plants can have cascading impacts on the establishment of new insect herbivore populations, their long-term population dynamics, and their invasion potential in novel habitats. Mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae) has recently expanded its range into forests of jack pine, Pinus banksiana Lamb., in western Canada. We investigated whether variations in jack pine monoterpenes affect beetle pheromone production, as the primary components of the beetle's aggregation pheromone, (-)-trans-verbenol and anti-aggregation pheromone (-)-verbenone, are biosynthesized from the host monoterpene α-pinene. Jack pine bolts were collected from five Canadian provinces east of the beetle's current range, live D. ponderosae were introduced into them, and their monoterpene compositions were characterized. Production of (-)-trans-verbenol and (-)-verbenone emitted by beetles was measured to determine whether pheromone production varies with monoterpene composition of jack pines. Depending on particular ratios of major monoterpenes in host phloem, jack pine could be classified into three monoterpenoid groups characterized by high amounts of (+)-α-pinene, 3-carene, or a more moderate blend of monoterpenes, and beetle pheromone production varied among these groups. Specifically, beetles reared in trees characterized by high (+)-α-pinene produced the most (-)-trans-verbenol and (-)-verbenone, while beetles in trees characterized by high 3-carene produced the least. Our results indicate that pheromone production by D. ponderosae will remain a significant aspect and important predictor of its survival and persistence in the boreal forest.

Indicator Expansion with Analysis Pipeline

DTIC Science & Technology

2015-01-13

INTERNAL FILTER trackInfectedHosts FILTER badTraffic SIP infectedHosts 1 DAY END INTERNAL FILTER 11 Step 3 watch where infected hosts go FILTER...nonWhiteListPostInfected SIP IN LIST infectedHosts DIP NOT IN LIST safePopularIPs.set END FILTER 12 Step 4 & 5: Count Hosts Per IP and Alert EVALUATION...CHECK THRESHOLD DISTINCT SIP > 50 TIME WINDOW 36 HOURS END CHECK END EVALUATION 13 Step 6: Report Expanded Indicators LIST CONFIGURATION secondLevelIPs

Diverse styles of submarine venting on the ultraslow spreading Mid-Cayman Rise

PubMed Central

German, C. R.; Bowen, A.; Coleman, M. L.; Honig, D. L.; Huber, J. A.; Jakuba, M. V.; Kinsey, J. C.; Kurz, M. D.; Leroy, S.; McDermott, J. M.; de Lépinay, B. Mercier; Nakamura, K.; Seewald, J. S.; Smith, J. L.; Sylva, S. P.; Van Dover, C. L.; Whitcomb, L. L.; Yoerger, D. R.

2010-01-01

Thirty years after the first discovery of high-temperature submarine venting, the vast majority of the global mid-ocean ridge remains unexplored for hydrothermal activity. Of particular interest are the world’s ultraslow spreading ridges that were the last to be demonstrated to host high-temperature venting but may host systems particularly relevant to prebiotic chemistry and the origins of life. Here we report evidence for previously unknown, diverse, and very deep hydrothermal vents along the ∼110 km long, ultraslow spreading Mid-Cayman Rise (MCR). Our data indicate that the MCR hosts at least three discrete hydrothermal sites, each representing a different type of water-rock interaction, including both mafic and ultramafic systems and, at ∼5,000 m, the deepest known hydrothermal vent. Although submarine hydrothermal circulation, in which seawater percolates through and reacts with host lithologies, occurs on all mid-ocean ridges, the diversity of vent types identified here and their relative geographic isolation make the MCR unique in the oceans. These new sites offer prospects for an expanded range of vent-fluid compositions, varieties of abiotic organic chemical synthesis and extremophile microorganisms, and unparalleled faunal biodiversity—all in close proximity. PMID:20660317

Boring in response to bark and phloem extracts from North American trees does not explain host acceptance behavior of Orthotomicus erosus (Coleoptera: Scolytidae).

PubMed

Walter, Abigail J; Kells, Stephen A; Venette, Robert C; Seybold, Steven J

2010-04-01

When invasive herbivorous insects encounter novel plant species, they must determine whether the novel plants are hosts. The Mediterranean pine engraver, Orthotomicus erosus (Wollaston), an exotic bark beetle poised to expand its range in North America, accepts hosts after contacting the bark. To test the hypothesis that O. erosus accepts hosts on the basis of gustatory cues, we prepared bark and phloem extracts from logs of four North American tree species that we had used in previous host acceptance experiments. Water, methanol, and hexane extracts of red pine, tamarack, balsam fir, and paper birch were presented alone and in combination on a neutral filter paper substrate in a section of a plastic drinking straw. Boring behavior in response to the three-extract combinations differed from the pattern of acceptance previously observed among species when the beetles were in contact with the bark surface. Only the aqueous extracts of tamarack, Larix laricina, increased the initiation and the extent of boring by O. erosus on the filter paper substrate. We conclude that the effects of extracted chemicals do not match the behavior of the beetles observed when penetrating excised bark and phloem discs, indicating that host selection by O. erosus may not be predictable from bark and phloem chemistry alone. Instead, host acceptance may be determined by nongustatory stimuli or by a combination of stimuli including gustatory and nongustatory cues.

Association of tomato leaf curl Gujarat virus and tomato leaf curl Bangladesh betasatellite on papaya showing typical leaf curl symptoms in North India.

PubMed

Varun, Priyanka; Saxena, Sangeeta

2018-05-01

Papaya leaf curl is an economically important disease occurring in papaya growing tropical and subtropical areas. Papaya leaf curl virus, a begomovirus, is the main causative agent for the disease, but many other begomoviruses as well as betasatellites have also been reported on papaya leaf curl disease. Rapidly evolving host range of begomoviruses is a major issue for developing successful resistance strategies against begomoviral infection considering their expanding host range and mixed infection. In our study, we have identified the presence of begomovirus and associated satellite molecule on papaya showing severe leaf curl symptoms in Lucknow, India. Analysis of complete DNA-A component of this isolate (MG757245) revealed the highest similarity (91%) with tomato leaf curl Gujarat virus (ToLCuGuV), while sequence data of betasatellite (MG478451) showed maximum (89%) identity with tomato leaf curl Bangladesh betasatellite (ToLCuBB). This is the first report on identification of ToLCuGuV and ToLCuBB coinfecting papaya plants in Lucknow, Uttar Pradesh (India).

Prevalence and Evolution of Core Photosystem II Genes in Marine Cyanobacterial Viruses and Their Hosts

PubMed Central

Lee, Jessica A; Thompson, Luke R; Bielawski, Joseph P

2006-01-01

Cyanophages (cyanobacterial viruses) are important agents of horizontal gene transfer among marine cyanobacteria, the numerically dominant photosynthetic organisms in the oceans. Some cyanophage genomes carry and express host-like photosynthesis genes, presumably to augment the host photosynthetic machinery during infection. To study the prevalence and evolutionary dynamics of this phenomenon, 33 cultured cyanophages of known family and host range and viral DNA from field samples were screened for the presence of two core photosystem reaction center genes, psbA and psbD. Combining this expanded dataset with published data for nine other cyanophages, we found that 88% of the phage genomes contain psbA, and 50% contain both psbA and psbD. The psbA gene was found in all myoviruses and Prochlorococcus podoviruses, but could not be amplified from Prochlorococcus siphoviruses or Synechococcus podoviruses. Nearly all of the phages that encoded both psbA and psbD had broad host ranges. We speculate that the presence or absence of psbA in a phage genome may be determined by the length of the latent period of infection. Whether it also carries psbD may reflect constraints on coupling of viral- and host-encoded PsbA–PsbD in the photosynthetic reaction center across divergent hosts. Phylogenetic clustering patterns of these genes from cultured phages suggest that whole genes have been transferred from host to phage in a discrete number of events over the course of evolution (four for psbA, and two for psbD), followed by horizontal and vertical transfer between cyanophages. Clustering patterns of psbA and psbD from Synechococcus cells were inconsistent with other molecular phylogenetic markers, suggesting genetic exchanges involving Synechococcus lineages. Signatures of intragenic recombination, detected within the cyanophage gene pool as well as between hosts and phages in both directions, support this hypothesis. The analysis of cyanophage psbA and psbD genes from field populations revealed significant sequence diversity, much of which is represented in our cultured isolates. Collectively, these findings show that photosynthesis genes are common in cyanophages and that significant genetic exchanges occur from host to phage, phage to host, and within the phage gene pool. This generates genetic diversity among the phage, which serves as a reservoir for their hosts, and in turn influences photosystem evolution. PMID:16802857

Interlayer-expanded molybdenum disulfide nanocomposites for electrochemical magnesium storage.

PubMed

Liang, Yanliang; Yoo, Hyun Deog; Li, Yifei; Shuai, Jing; Calderon, Hector A; Robles Hernandez, Francisco Carlos; Grabow, Lars C; Yao, Yan

2015-03-11

Mg rechargeable batteries (MgRBs) represent a safe and high-energy battery technology but suffer from the lack of suitable cathode materials due to the slow solid-state diffusion of the highly polarizing divalent Mg ion. Previous methods improve performance at the cost of incompatibility with anode/electrolyte and drastic decrease in volumetric energy density. Herein we report interlayer expansion as a general and effective atomic-level lattice engineering approach to transform inactive intercalation hosts into efficient Mg storage materials without introducing adverse side effects. As a proof-of-concept we have combined theory, synthesis, electrochemical measurement, and kinetic analysis to improve Mg diffusion behavior in MoS2, which is a poor Mg transporting material in its pristine form. First-principles simulations suggest that expanded interlayer spacing allows for fast Mg diffusion because of weakened Mg-host interactions. Experimentally, the expansion was realized by inserting a controlled amount of poly(ethylene oxide) into the lattice of MoS2 to increase the interlayer distance from 0.62 nm to up to 1.45 nm. The expansion boosts Mg diffusivity by 2 orders of magnitude, effectively enabling the otherwise barely active MoS2 to approach its theoretical storage capacity as well as to achieve one of the highest rate capabilities among Mg-intercalation materials. The interlayer expansion approach can be leveraged to a wide range of host materials for the storage of various ions, leading to novel intercalation chemistry and opening up new opportunities for the development of advanced materials for next-generation energy storage.

Genetic engineering of a temperate phage-based delivery system for CRISPR/Cas9 antimicrobials against Staphylococcus aureus

PubMed Central

Park, Joo Youn; Moon, Bo Youn; Park, Juw Won; Thornton, Justin A.; Park, Yong Ho; Seo, Keun Seok

2017-01-01

Discovery of clustered, regularly interspaced, short palindromic repeats and the Cas9 RNA-guided nuclease (CRISPR/Cas9) system provides a new opportunity to create programmable gene-specific antimicrobials that are far less likely to drive resistance than conventional antibiotics. However, the practical therapeutic use of CRISPR/Cas9 is still questionable due to current shortcomings in phage-based delivery systems such as inefficient delivery, narrow host range, and potential transfer of virulence genes by generalized transduction. In this study, we demonstrate genetic engineering strategies to overcome these shortcomings by integrating CRISPR/Cas9 system into a temperate phage genome, removing major virulence genes from the host chromosome, and expanding host specificity of the phage by complementing tail fiber protein. This significantly improved the efficacy and safety of CRISPR/Cas9 antimicrobials to therapeutic levels in both in vitro and in vivo assays. The genetic engineering tools and resources established in this study are expected to provide an efficacious and safe CRISPR/Cas9 antimicrobial, broadly applicable to Staphylococcus aureus. PMID:28322317

Genetic engineering of a temperate phage-based delivery system for CRISPR/Cas9 antimicrobials against Staphylococcus aureus.

PubMed

Park, Joo Youn; Moon, Bo Youn; Park, Juw Won; Thornton, Justin A; Park, Yong Ho; Seo, Keun Seok

2017-03-21

Discovery of clustered, regularly interspaced, short palindromic repeats and the Cas9 RNA-guided nuclease (CRISPR/Cas9) system provides a new opportunity to create programmable gene-specific antimicrobials that are far less likely to drive resistance than conventional antibiotics. However, the practical therapeutic use of CRISPR/Cas9 is still questionable due to current shortcomings in phage-based delivery systems such as inefficient delivery, narrow host range, and potential transfer of virulence genes by generalized transduction. In this study, we demonstrate genetic engineering strategies to overcome these shortcomings by integrating CRISPR/Cas9 system into a temperate phage genome, removing major virulence genes from the host chromosome, and expanding host specificity of the phage by complementing tail fiber protein. This significantly improved the efficacy and safety of CRISPR/Cas9 antimicrobials to therapeutic levels in both in vitro and in vivo assays. The genetic engineering tools and resources established in this study are expected to provide an efficacious and safe CRISPR/Cas9 antimicrobial, broadly applicable to Staphylococcus aureus.

Efficient active-template synthesis of calix[6]arene-based oriented pseudorotaxanes and rotaxanes.

PubMed

Zanichelli, Valeria; Ragazzon, Giulio; Orlandini, Guido; Venturi, Margherita; Credi, Alberto; Silvi, Serena; Arduini, Arturo; Secchi, Andrea

2017-08-16

A substrate can modify its chemical features, including a change of its reactivity, as a consequence of non-covalent interactions upon inclusion within a molecular host. Since the rise of supramolecular chemistry, this phenomenon has stimulated the ingenuity of scientists to emulate the function of enzymes by designing supramolecular systems in which the energetics and selectivity of reactions can be manipulated through programmed host-guest interactions and/or steric confinement. In this paper we investigate how the engulfment of a positively charged pyridinium-based guest inside the π-rich cavity of a tris-(N-phenylureido)calix[6]arene host affects its reactivity towards a S N 2 reaction. We found that the alkylation of complexed substrates leads to the formation of pseudorotaxanes and rotaxanes with faster kinetics and higher yields with respect to the standard procedures exploited so far. More importantly, the strategy described here expands the range of efficient synthetic routes for the formation of mechanically interlocked species with a strict control of the mutual orientation of their non-symmetric molecular components.

Characterization of Canna yellow mottle virus in a New Host, Alpinia purpurata, in Hawaii.

PubMed

Zhang, Jingxin; Dey, Kishore K; Lin, Birun; Borth, Wayne B; Melzer, Michael J; Sether, Diane; Wang, Yanan; Wang, I-Chin; Shen, Huifang; Pu, Xiaoming; Sun, Dayuan; Hu, John S

2017-06-01

Canna yellow mottle virus (CaYMV) is an important badnavirus infecting Canna spp. worldwide. This is the first report of CaYMV in flowering ginger (Alpinia purpurata) in Hawaii, where it is associated with yellow mottling and necrosis of leaves, vein streaking, and stunted plants. We have sequenced CaYMV in A. purpurata (CaYMV-Ap) using a combination of next-generation sequencing and traditional Sanger sequencing techniques. The complete genome of CaYMV-Ap was 7,120 bp with an organization typical of other Badnavirus species. Our results indicated that CaYMV-Ap was present in the episomal form in infected flowering ginger. We determined that this virus disease is prevalent in Hawaii and could potentially have significant economic impact on the marketing of A. purpurata as cut flowers. There is a potential concern that the host range of CaYMV-Ap may expand to include other important tropical plants.

Infectious diseases of fishes in the Salish Sea

USGS Publications Warehouse

Hershberger, Paul; Rhodes, Linda; Kurath, Gael; Winton, James

2013-01-01

As in marine regions throughout other areas of the world, fishes in the Salish Sea serve as hosts for many pathogens, including nematodes, trematodes, protozoans, protists, bacteria, viruses, and crustaceans. Here, we review some of the better-documented infectious diseases that likely contribute to significant losses among free-ranging fishes in the Salish Sea and discuss the environmental and ecological factors that may affect the population-level impacts of disease. Demonstration of these diseases and their impacts to critical and endangered resources provides justification to expand pathogen surveillance efforts and to incorporate disease forecasting and mitigation tools into ecosystem restoration efforts.

Public affairs events at Fall Meeting

NASA Astrophysics Data System (ADS)

Uhlenbrock, Kristan

2012-02-01

AGU's Public Affairs team presented two workshop luncheons and hosted 17 oral and poster sessions at the 2011 Fall Meeting. Topics ranged from defining the importance of the geosciences, to climate change science for communities and institutions. The workshop luncheon "How to Be a Congressional Science Fellow or Mass Media Fellow" was a well-attended event with more than 115 participants. The luncheon provided the opportunity for audience members to ask fellow scientists about their experiences working either in Congress or as a reporter for a news organization. For scientists looking to expand their expertise outside the academic environment, these AGU fellowships are fantastic opportunities.

EosFit-Pinc: a GUI program to calculate pressures in host-inclusion systems

NASA Astrophysics Data System (ADS)

Angel, Ross; Alvaro, Matteo; Mazzucchelli, Mattia; Nestola, Fabrizio

2017-04-01

A remnant pressure in an inclusion trapped inside a host mineral is developed because the inclusion and the host have different thermal expansion and compressibilities, and the inclusion does not expand in response to P and T as would a free crystal. Instead it is restricted to expand only as much as the cavity of the host mineral, and this constriction in volume can result in inclusions exhibiting over-pressures when the host is studied at room conditions. The remnant pressure of the inclusion, measured by X-ray diffractometry, birefringence analysis or Raman spectroscopy, can then be used with the equations of state (EoS) of the host and inclusion to constrain the P and T at entrapment. This concept has been known for a long time, but satisfactory quantitative modelling of inclusion-host systems based on non-linear elasticity theory and precise EoS has only recently come available (Angel et al., 2014, 2015), even though calculations still assume isotropic elastic properties. The elasticity calculations to determine entrapment conditions involving the EoSs for both the host and the inclusion are complex if thermodynamically-realistic EoS are employed. We have therefore developed a simple GUI program, EosFit-Pinc that performs all of the necessary calculations under the assumptions of isotropic elasticity. Equations of state of the host and the inclusion can be loaded as files created by other software in the EosFit7 program suite, or imported directly from thermodynamic databases such as Thermocalc. The complete range of EoS types supported by EosFit-7 are available in EosFit-Pinc. Fluid EoS can be provided in the form of PVT tables, which allows fluid inclusions to be modelled. Once loaded, the EoS of the host and inclusion can be used to calculate the entrapment isomeke from the measured remnant pressure of the inclusion. Or the final pressure can be calculated if the entrapment conditions are known or estimated. Calculations of the isochors of both the host and inclusion phases, and their mutual isomekes, can be performed, and output is provided in a format suitable for external plotting programs. The program EosFit-Pinc and the EosFit7 program suite are available at www.rossangel.net This work was supported by ERC starting grant "INDIMEDEA" (307322) to F. Nestola and by the MIUR-SIR grant "MILE DEEp" (RBSI140351) to M. Alvaro. Angel R.J., Mazzucchelli M.L., Alvaro M., Nimis P. & Nestola F. (2014) Geobarometry from host-inclusion systems: the role of elastic relaxation. Am. Mineral., 99, 2146-2149. Angel R.J., Nimis P., Mazzucchelli M.L., Alvaro M. & Nestola F. (2015) How large are departures from lithostatic pressure? Constraints from host-inclusion elasticity. J. Metamorphic Geol., 33, 801-813.

Defence syndromes in lodgepole - whitebark pine ecosystems relate to degree of historical exposure to mountain pine beetles.

PubMed

Raffa, Kenneth F; Mason, Charles J; Bonello, Pierluigi; Cook, Stephen; Erbilgin, Nadir; Keefover-Ring, Ken; Klutsch, Jennifer G; Villari, Caterina; Townsend, Philip A

2017-09-01

Warming climate is allowing tree-killing bark beetles to expand their ranges and access naïve and semi-naïve conifers. Conifers respond to attack using complex mixtures of chemical defences that can impede beetle success, but beetles exploit some compounds for host location and communication. Outcomes of changing relationships will depend on concentrations and compositions of multiple host compounds, which are largely unknown. We analysed constitutive and induced chemistries of Dendroctonus ponderosae's primary historical host, Pinus contorta, and Pinus albicaulis, a high-elevation species whose encounters with this beetle are transitioning from intermittent to continuous. We quantified multiple classes of terpenes, phenolics, carbohydrates and minerals. Pinus contorta had higher constitutive allocation to, and generally stronger inducibility of, compounds that resist these beetle-fungal complexes. Pinus albicaulis contained higher proportions of specific monoterpenes that enhance pheromone communication, and lower induction of pheromone inhibitors. Induced P. contorta increased insecticidal and fungicidal compounds simultaneously, whereas P. albicaulis responses against these agents were inverse. Induced terpene accumulation was accompanied by decreased non-structural carbohydrates, primarily sugars, in P. contorta, but not P. albicaulis, which contained primarily starches. These results show some host species with continuous exposure to bark beetles have more thoroughly integrated defence syndromes than less-continuously exposed host species. © 2017 John Wiley & Sons Ltd.

Use of a secondary host by non-outbreak populations of the gypsy moth. [Pinus rigida; Quercus spp; Lymantria dispar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rossiter, M.

1987-08-01

Oaks are the favored host of gypsy moths in the northeastern US, although the herbivore expands its host range dramatically during an outbreak. Pitch pine, a secondary host because of its unacceptability for early development, was found to be frequently used for oviposition in oak-pitch pine forests with non-outbreak populations. This observation led to the study of ecological and behavioral factors that can contribute to the use of a secondary host under low-density conditions by an irruptive herbivore species. A series of manipulative field and laboratory experiments plus a study of natural history provided data on the pattern of pitchmore » pine use during the life cycle of the gypsy moth, the effect of pitch pine on larval growth, and the differential impact of natural enemies depending on host use. It was found that: 1) egg masses occurred far more frequently on pitch pine than was expected based on the frequency of pitch pine in forests with low-density gypsy moth populations; 2) in the laboratory, early-instar larvae could not survive on pitch pine while late-instar larvae grew well; 3) in the field, larvae began to use pitch pine to feed and rest after the onset of the fourth instar. Compared to oak, 4) egg masses on pitch pine experienced less parasitism; 5) the microhabitat of pitch pine held less nuclear polyhedrosis virus (NPV), a major mortality agent of the gypsy moth; 6) individuals hatching from eggs laid on pitch pine were less infected with NPV; and 7) larvae dosed with a known amount of NPV survived longer when feeding on pitch pine foliage. The use of pitch pine by individuals in low-density gypsy moth populations appeared to be beneficial and may have an important effect on population dynamics. The mobility associated with host switching by late-instar larvae and with dispersal by first-instar larvae oviposited on unacceptable food may represent an important mechanism for host-range extension.« less

Origin of Pest Lineages of the Colorado Potato Beetle (Coleoptera: Chrysomelidae).

PubMed

Izzo, Victor M; Chen, Yolanda H; Schoville, Sean D; Wang, Cong; Hawthorne, David J

2018-04-02

Colorado potato beetle (Leptinotarsa decemlineata Say [Coleoptera: Chrysomelidae]) is a pest of potato throughout the Northern Hemisphere, but little is known about the beetle's origins as a pest. We sampled the beetle from uncultivated Solanum host plants in Mexico, and from pest and non-pest populations in the United States and used mitochondrial DNA and nuclear loci to examine three hypotheses on the origin of the pest lineages: 1) the pest beetles originated from Mexican populations, 2) they descended from hybridization between previously divergent populations, or 3) they descended from populations that are native to the Plains states in the United States. Mitochondrial haplotypes of non-pest populations from Mexico and Arizona differed substantially from beetles collected from the southern plains and potato fields in the United States, indicating that beetles from Mexico and Arizona did not contribute to founding the pest lineages. Similar results were observed for AFLP and microsatellite data . In contrast, non-pest populations from the states of Colorado, Kansas, Nebraska, New Mexico, and Texas were genetically similar to U.S. pest populations, indicating that they contributed to the founding of the pest lineages. Most of the pest populations do not show a significant reduction in genetic diversity compared to the plains populations in the United States. We conclude that genetically heterogeneous beetle populations expanded onto potato from native Solanum hosts. This mode of host range expansion may have contributed to the abundant genetic diversity of contemporary populations, perhaps contributing to the rapid evolution of climate tolerance, host range, and insecticide resistance.

Crop domestication facilitated rapid geographical expansion of a specialist pollinator, the squash bee Peponapis pruinosa.

PubMed

López-Uribe, Margarita M; Cane, James H; Minckley, Robert L; Danforth, Bryan N

2016-06-29

Squash was first domesticated in Mexico and is now found throughout North America (NA) along with Peponapis pruinosa, a pollen specialist bee species of the squash genus Cucurbita The origin and spread of squash cultivation is well-studied archaeologically and phylogenetically; however, no study has documented how cultivation of this or any other crop has influenced species in mutualistic interactions. We used molecular markers to reconstruct the demographic range expansion and colonization routes of P. pruinosa from its native range into temperate NA. Populations east of the Rocky Mountains expanded from the wild host plant's range in Mexico and were established by a series of founder events. Eastern North America was most likely colonized from squash bee populations in the present-day continental Midwest USA and not from routes that followed the Gulf and Atlantic coasts from Mexico. Populations of P. pruinosa west of the Rockies spread north from the warm deserts much more recently, showing two genetically differentiated populations with no admixture: one in California and the other one in eastern Great Basin. These bees have repeatedly endured severe bottlenecks as they colonized NA, following human spread of their Cucurbita pollen hosts during the Holocene. © 2016 The Author(s).

Thicker host tissues moderate light stress in a cnidarian endosymbiont.

PubMed

Dimond, James L; Holzman, Benjamin J; Bingham, Brian L

2012-07-01

The susceptibility of algal-cnidarian holobionts to environmental stress is dependent on attributes of both host and symbiont, but the role of the host is often unclear. We examined the influence of the host on symbiont light stress, comparing the photophysiology of the chlorophyte symbiont Elliptochloris marina in two species of sea anemones in the genus Anthopleura. After 3 months of acclimation in outdoor tanks, polyp photoprotective contraction behavior was similar between the two host species, but photochemical efficiency was 1.5 times higher in A. xanthogrammica than in A. elegantissima. Maximum relative electron transport rates, derived from rapid light curves, were 1.5 times higher in A. xanthogrammica than in A. elegantissima when symbionts were inside intact tissues, but were not significantly different between host species upon removal of outer (epidermis and mesoglea) tissue layers from symbiont-containing gastrodermal cells. Tissues of A. xanthogrammica were 1.8 times thicker than those of A. elegantissima, with outer tissue layers attenuating 1.6 times more light. We found no significant differences in light absorption properties per unit volume of tissue, confirming the direct effect of tissue thickness on light attenuation. The thicker tissues of A. xanthogrammica thus provide a favorable environment for E. marina - a relatively stress-susceptible symbiont - and may explain its higher prevalence and expanded range in A. xanthogrammica along the Pacific coast of North America. Our findings also support a photoprotective role for thicker host tissues in reef corals that has long been thought to influence variability in bleaching susceptibility among coral taxa.

Mesoamerican Origin and Pre- and Post-Columbian Expansions of the Ranges of Acanthoscelides obtectus Say, a Cosmopolitan Insect Pest of the Common Bean

PubMed Central

Oliveira, Márcia Rodrigues Carvalho; Corrêa, Alberto Soares; de Souza, Giselle Anselmo; Guedes, Raul Narciso Carvalho; de Oliveira, Luiz Orlando

2013-01-01

An unprecedented global transfer of agricultural resources followed the discovery of the New World; one consequence of this process was that staple food plants of Neotropical origin, such as the common bean (Phaseolus vulgaris), soon expanded their ranges overseas. Yet many pests and diseases were also transported. Acanthoscelides obtectus is a cosmopolitan seed predator associated with P. vulgaris. Codispersal within the host seed seems to be an important determinant of the ability of A. obtectus to expand its range over long distances. We examined the phylogeographic structure of A. obtectus by (a) sampling three mitochondrial gene sequences (12s rRNA, 16s rRNA, and the gene that encodes cytochrome c oxidase subunit I (COI)) throughout most of the species’ range and (b) exploring its late evolutionary history. Our findings indicate a Mesoamerican origin for the current genealogical lineages of A. obtectus. Each of the two major centers of genetic diversity of P. vulgaris (the Andes and Mesoamerica) contains a highly differentiated lineage of the bean beetle. Brazil has two additional, closely related lineages, both of which predate the Andean lineage and have the Mesoamerican lineage as their ancestor. The cosmopolitan distribution of A. obtectus has resulted from recent expansions of the two Brazilian lineages. We present additional evidence for both pre-Columbian and post-Columbian range expansions as likely events that shaped the current distribution of A. obtectus worldwide. PMID:23936139

Molecular Epidemiology of Blastocystis sp. in Various Animal Groups from Two French Zoos and Evaluation of Potential Zoonotic Risk

PubMed Central

Moriniere, Romain; Gantois, Nausicaa; Benamrouz-Vanneste, Sadia; Delgado-Viscogliosi, Pilar; Guyot, Karine; Li, Luen-Luen; Monchy, Sébastien; Noël, Christophe; Poirier, Philippe; Nourrisson, Céline; Wawrzyniak, Ivan; Delbac, Frédéric; Bosc, Stéphanie; Chabé, Magali; Petit, Thierry; Certad, Gabriela; Viscogliosi, Eric

2017-01-01

Blastocystis sp. is a common intestinal parasite infecting humans and a wide range of animals worldwide. It exhibits an extensive genetic diversity and 17 subtypes (STs) have thus far been identified in mammalian and avian hosts. Since several STs are common to humans and animals, it was proposed that a proportion of human infections may result from zoonotic transmission. However, the contribution of each animal source to human infection remains to be clarified. Therefore, the aim of this study was to expand our knowledge of the epidemiology and host specificity of this parasite by performing the largest epidemiological survey ever conducted in animal groups in terms of numbers of species screened. A total of 307 stool samples from 161 mammalian and non-mammalian species in two French zoos were screened by real-time PCR for the presence of Blastocystis sp. Overall, 32.2% of the animal samples and 37.9% of the species tested were shown to be infected with the parasite. A total of 111 animal Blastocystis sp. isolates were subtyped, and 11 of the 17 mammalian and avian STs as well as additional STs previously identified in reptiles and insects were found with a varying prevalence according to animal groups. These data were combined with those obtained from previous surveys to evaluate the potential risk of zoonotic transmission of Blastocystis sp. through the comparison of ST distribution between human and animal hosts. This suggests that non-human primates, artiodactyls and birds may serve as reservoirs for human infection, especially in animal handlers. In contrast, other mammals such as carnivores, and non-mammalian groups including reptiles and insects, do not seem to represent significant sources of Blastocystis sp. infection in humans. In further studies, more intensive sampling and screening of potential new animal hosts will reinforce these statements and expand our understanding of the circulation of Blastocystis sp. in animal and human populations. PMID:28060901

Molecular Epidemiology of Blastocystis sp. in Various Animal Groups from Two French Zoos and Evaluation of Potential Zoonotic Risk.

PubMed

Cian, Amandine; El Safadi, Dima; Osman, Marwan; Moriniere, Romain; Gantois, Nausicaa; Benamrouz-Vanneste, Sadia; Delgado-Viscogliosi, Pilar; Guyot, Karine; Li, Luen-Luen; Monchy, Sébastien; Noël, Christophe; Poirier, Philippe; Nourrisson, Céline; Wawrzyniak, Ivan; Delbac, Frédéric; Bosc, Stéphanie; Chabé, Magali; Petit, Thierry; Certad, Gabriela; Viscogliosi, Eric

2017-01-01

Blastocystis sp. is a common intestinal parasite infecting humans and a wide range of animals worldwide. It exhibits an extensive genetic diversity and 17 subtypes (STs) have thus far been identified in mammalian and avian hosts. Since several STs are common to humans and animals, it was proposed that a proportion of human infections may result from zoonotic transmission. However, the contribution of each animal source to human infection remains to be clarified. Therefore, the aim of this study was to expand our knowledge of the epidemiology and host specificity of this parasite by performing the largest epidemiological survey ever conducted in animal groups in terms of numbers of species screened. A total of 307 stool samples from 161 mammalian and non-mammalian species in two French zoos were screened by real-time PCR for the presence of Blastocystis sp. Overall, 32.2% of the animal samples and 37.9% of the species tested were shown to be infected with the parasite. A total of 111 animal Blastocystis sp. isolates were subtyped, and 11 of the 17 mammalian and avian STs as well as additional STs previously identified in reptiles and insects were found with a varying prevalence according to animal groups. These data were combined with those obtained from previous surveys to evaluate the potential risk of zoonotic transmission of Blastocystis sp. through the comparison of ST distribution between human and animal hosts. This suggests that non-human primates, artiodactyls and birds may serve as reservoirs for human infection, especially in animal handlers. In contrast, other mammals such as carnivores, and non-mammalian groups including reptiles and insects, do not seem to represent significant sources of Blastocystis sp. infection in humans. In further studies, more intensive sampling and screening of potential new animal hosts will reinforce these statements and expand our understanding of the circulation of Blastocystis sp. in animal and human populations.

H5N1 pathogenesis studies in mammalian models

PubMed Central

Belser, Jessica A.; Tumpey, Terrence M.

2017-01-01

H5N1 influenza viruses are capable of causing severe disease and death in humans, and represent a potential pandemic subtype should they acquire a transmissible phenotype. Due to the expanding host and geographic range of this virus subtype, there is an urgent need to better understand the contribution of both virus and host responses following H5N1 virus infection to prevent and control human disease. The use of mammalian models, notably the mouse and ferret, has enabled the detailed study of both complex virus–host interactions as well as the contribution of individual viral proteins and point mutations which influence virulence. In this review, we describe the behavior of H5N1 viruses which exhibit high and low virulence in numerous mammalian species, and highlight the contribution of inoculation route to virus pathogenicity. The involvement of host responses as studied in both inbred and outbred mammalian models is discussed. The roles of individual viral gene products and molecular determinants which modulate the severity of H5N1 disease in vivo are presented. This research contributes not only to our understanding of influenza virus pathogenesis, but also identifies novel preventative and therapeutic targets to mitigate the disease burden caused by avian influenza viruses. PMID:23458998

Investigating Gene Function in Cereal Rust Fungi by Plant-Mediated Virus-Induced Gene Silencing.

PubMed

Panwar, Vinay; Bakkeren, Guus

2017-01-01

Cereal rust fungi are destructive pathogens, threatening grain production worldwide. Targeted breeding for resistance utilizing host resistance genes has been effective. However, breakdown of resistance occurs frequently and continued efforts are needed to understand how these fungi overcome resistance and to expand the range of available resistance genes. Whole genome sequencing, transcriptomic and proteomic studies followed by genome-wide computational and comparative analyses have identified large repertoire of genes in rust fungi among which are candidates predicted to code for pathogenicity and virulence factors. Some of these genes represent defence triggering avirulence effectors. However, functions of most genes still needs to be assessed to understand the biology of these obligate biotrophic pathogens. Since genetic manipulations such as gene deletion and genetic transformation are not yet feasible in rust fungi, performing functional gene studies is challenging. Recently, Host-induced gene silencing (HIGS) has emerged as a useful tool to characterize gene function in rust fungi while infecting and growing in host plants. We utilized Barley stripe mosaic virus-mediated virus induced gene silencing (BSMV-VIGS) to induce HIGS of candidate rust fungal genes in the wheat host to determine their role in plant-fungal interactions. Here, we describe the methods for using BSMV-VIGS in wheat for functional genomics study in cereal rust fungi.

Converging free energies of binding in cucurbit[7]uril and octa-acid host-guest systems from SAMPL4 using expanded ensemble simulations

NASA Astrophysics Data System (ADS)

Monroe, Jacob I.; Shirts, Michael R.

2014-04-01

Molecular containers such as cucurbit[7]uril (CB7) and the octa-acid (OA) host are ideal simplified model test systems for optimizing and analyzing methods for computing free energies of binding intended for use with biologically relevant protein-ligand complexes. To this end, we have performed initially blind free energy calculations to determine the free energies of binding for ligands of both the CB7 and OA hosts. A subset of the selected guest molecules were those included in the SAMPL4 prediction challenge. Using expanded ensemble simulations in the dimension of coupling host-guest intermolecular interactions, we are able to show that our estimates in most cases can be demonstrated to fully converge and that the errors in our estimates are due almost entirely to the assigned force field parameters and the choice of environmental conditions used to model experiment. We confirm the convergence through the use of alternative simulation methodologies and thermodynamic pathways, analyzing sampled conformations, and directly observing changes of the free energy with respect to simulation time. Our results demonstrate the benefits of enhanced sampling of multiple local free energy minima made possible by the use of expanded ensemble molecular dynamics and may indicate the presence of significant problems with current transferable force fields for organic molecules when used for calculating binding affinities, especially in non-protein chemistries.

Converging free energies of binding in cucurbit[7]uril and octa-acid host-guest systems from SAMPL4 using expanded ensemble simulations.

PubMed

Monroe, Jacob I; Shirts, Michael R

2014-04-01

Molecular containers such as cucurbit[7]uril (CB7) and the octa-acid (OA) host are ideal simplified model test systems for optimizing and analyzing methods for computing free energies of binding intended for use with biologically relevant protein-ligand complexes. To this end, we have performed initially blind free energy calculations to determine the free energies of binding for ligands of both the CB7 and OA hosts. A subset of the selected guest molecules were those included in the SAMPL4 prediction challenge. Using expanded ensemble simulations in the dimension of coupling host-guest intermolecular interactions, we are able to show that our estimates in most cases can be demonstrated to fully converge and that the errors in our estimates are due almost entirely to the assigned force field parameters and the choice of environmental conditions used to model experiment. We confirm the convergence through the use of alternative simulation methodologies and thermodynamic pathways, analyzing sampled conformations, and directly observing changes of the free energy with respect to simulation time. Our results demonstrate the benefits of enhanced sampling of multiple local free energy minima made possible by the use of expanded ensemble molecular dynamics and may indicate the presence of significant problems with current transferable force fields for organic molecules when used for calculating binding affinities, especially in non-protein chemistries.

Definitive hosts of a fatal Versteria species (Cestoda: Taeniidae) in North America

USDA-ARS?s Scientific Manuscript database

We previously reported fatal metacestode infection in a captive orangutan (Pongo pygmaeus) with a novel taeniid tapeworm, Versteria sp. Data from ermine (Mustela erminea) and mink (Neovison vison) implicate mustelids as definitive North America hosts and expand known Versteria diversity. The orangu...

hwhap_Ep39 BEAM and Expandable Spacecraft

NASA Image and Video Library

2018-04-06

Gary Jordan (Host): Houston, We Have A Podcast. Welcome to the official podcast of the NASA Johnson Space Center, episode 39, BEAM and Expandable Spacecraft. I'm Gary Jordan and I'll be your host today. So, this is the podcast where we bring in the experts. You know this, guys. NASA scientists, engineers, astronauts, all to let you know the information-- the coolest info right here at NASA. So, today we're talking about expandable tech and expandable modules and a commercial module on the International Space Station right now called BEAM, or the Bigelow Expandable Activity Module. We're talking with Rajib Dasgupta and Gerard Valle. Rajib Dasgupta is now the material process engineering system manager for commercial crew, but he was the former project manager for BEAM through most of the beginning of the project. And Gerard Valle is now the project manager for the project. He used to be the BEAM structures lead. We talked about the beginning of the project with Rajib and more on what BEAM and expandable modules are made of, how they work, and what's in store for the future with Gerard. Thanks to Max exclamation point on Twitter for the suggestion to do an episode on BEAM. So, with no further delay, let's go light speed and jump right ahead to our talk with Mr. Rajib Dasgupta and Mr. Gerard Valle. Enjoy. [ Music ] Host: We'll talk about BEAM today. So, basically the Bigelow Expandable Activity Module, right, that's the acronym. I had to make sure I memorized that before today. So, the whole idea was basically it's an expandable module, not like the aluminum shell that comes up exactly like it's sent up, this thing is expanding, right? That's the whole purpose of the expandable technology? Rajib Dasgupta: Correct. Host: OK. So, then when did this all start? When-- how did expandable tech come to be? Rajib Dasgupta: Well, expandable technology from a NASA standpoint started around mid-90's, 1995, 1996-- 1996 to be precise with the TransHab project when NASA embarked in a pretty large-scale development project into space inflatables and expandables. And the whole concept of expandable was design a habitable structure with of soft goods, nonmetallics, for it to be lightweight. And also, the other concept was to have a very small launch volume, typically in the ratio of 20-25% of the full expanded volume, which you can pack pretty tightly and then launch using minimum storage space in the launch vehicle in the fairing and then once you're in orbit you expand it and get the full volume. So, essentially two benefits. Host: All right. Rajib Dasgupta: One is the smaller volume for launch and the other one is lightweight, of course. Host: Makes a lot of sense because you-- even with a larger module, it has to fit in this-- in the fairing, right? OK. So, that's a huge benefit because you can launch something a lot larger, right, and then kind of pack it down. Rajib Dasgupta: Pack it down. Host: So-- Rajib Dasgupta: And, in fact, the smaller ball-- the fact that we could pack BEAM to its smaller volume enabled us to launch in the cargo Dragon trunk. Because the trunk-- the cargo trunk only had so much space and the packed BEAM was about the largest volume you could launch in the cargo Dragon. Host: I'm imagining an analogy. I'm imagining like if you're going on a camping trip, you wouldn't pack your tent fully, you know, set up in the back of your trunk. You have to collapse it first. Rajib Dasgupta: Collapse it, yes. Very similar concept. Host: OK, yeah. But that was the idea, right? You didn't have to-- you didn't have to purchase a larger vehicle. It could be shipped up in the trunk of the SpaceX with fully pressurized cargo on the other side, right? Rajib Dasgupta: Absolutely. With our existing launch capabilities. Host: Oh, amazing. All right. So, going back to TransHab. Rajib Dasgupta: Right. Host: So, the beginning of this idea of expandable technology. What was the project there, this development project? Rajib Dasgupta: It was basically to develop a very large-scale expandable. Host: OK. Rajib Dasgupta: Or inflatable. Much larger than BEAM. Host: Oh, OK. Rajib Dasgupta: But a full-scale space station compatible hab module to be completely made of an, you know, expandable structure. That was the whole purpose. And that enabled us to do some very detailed research and development and testing of expandable and inflatable materials and structures. And that went on for three years through '99 when Congress decided to cancel that program. At which point, NASA actually licensed the patent-- there were three patents that came out of that whole effort and then after that-- after the cancellation of the TransHab program, NASA decided to license the patents to Mr. Bigelow in Bigelow Aerospace and that's how Bigelow Aerospace really got into this kind of technology development and they further developed it into a mission-ready flight-ready structure. OK? Host: I see. So, there's three licensed NASA technologies that are now over in Bigelow's hands and that's what they used to develop the expandable module that we see on the space station today? Rajib Dasgupta: Well, they did further developments on that. Host: I see. Rajib Dasgupta: But they took the, you know, that was their baseline. Host: OK. Rajib Dasgupta: That was their starting point. And then they did further testing and development, obviously, and that, you know, that involved to my knowledge significant amount of private enterprise funding from Mr. Bigelow to develop those technologies from that starting point into something that we could fly on station. Host: OK. And a lot of it-- and a lot of it has to do with-- and we can get more into this when we talk with Gerard, too. But more of the structure itself is a lot of layers. Is that part of the technology? Rajib Dasgupta: Yes. Host: OK. Rajib Dasgupta: It comprises of several layers, each performing its own function. Host: That's right. Yeah. And about consolidating that, but each one, like you said, serves its own function so you kind of need that. OK. So, then how did the concept for BEAM start? When did we start moving from licensing this-- Rajib Dasgupta: So, happened in 2010. Host: OK. Rajib Dasgupta: Precisely in April or May of 2010-- April 2010 when NASA-- for the ISS program, NASA Headquarters had what is called a broad-agency announcement, which is call-- like, simply like call for proposal-- Host: OK. Rajib Dasgupta: For ISS technology development and research, right? And then-- so, Bigelow Aerospace did provide a detailed proposal in that call and proposed that they would fly a small-scale inflatable habitat or expandable habitat on station for technology demonstration. So, that's when it started, 2010, in the mid-April timeframe. And then we got that proposal on the NASA ISS program side and did feasibility assessment from that and then that's how it started, basically. Host: So, Bigelow and NASA have been working pretty closely then from 2010-- Rajib Dasgupta: From 2010 onwards. Host: OK. So-- and how was the relationship there? It was mostly I guess Bigelow doing a lot of the technology development, but what was NASA's role? Rajib Dasgupta: Yeah. So, Bigelow was doing most of the technology development of the expandable structure, but NASA's role was to integrate that structure onto the ISS in a safe-- in a safe manner, which does not, you know, compromise the safety and integrity-- structural integrity of ISS. Host: OK. Rajib Dasgupta: So, that was NASA's role mainly. So, integrate that expandable structure onto the launch vehicle, which is Dragon and Falcon, and then on orbit deploy it and deploy it safely and demonstrate the technology for Bigelow. Host: So, there were a lot of I guess constraints for sizing because it had to fit in a launch vehicle, right? But then also for the way it connected, making sure that all the hooks and switches connected, it was going to get power, it was going to get atmosphere, all of that kind of stuff, right? So, then I guess there were-- did NASA have to do a lot with the fault safes I guess? Because, you know, making sure that-- this is a test technology, so making sure that you're right and if-- in instance that there were some sort of instance where you would need to shut it off, I guess-- were you developing procedures for that or technology for that? Rajib Dasgupta: Yeah. Oh, yeah. Host: So, what were some of the things? Rajib Dasgupta: Well, you know, some of the things-- like, for example-- just you said the size, right? So, the size-- very interestingly enough, the size of BEAM was tailored according to what we could launch in Dragon. So, Bigelow came up-- the original proposal had a different size. So, we had to resize it so we could launch it in Dragon. OK? So, that's one. Then the connection, you talked about the mechanical and electrical connection. So, NASA provided through another commercial company called Sierra Nevada a port-- a common porting mechanism that Bigelow attached to their module so that that common porting mechanism could attach the BEAM module to Node-3 aft. So, as you know, we have common attach mechanisms on ISS, so we had to provide that. OK? So, those are the two examples of, you know, what we had to integrate, but there were several other things, like loads and dynamics. And when it would deploy, we needed to make sure that the deployment activity or the deployment did not impart a lot of dynamic loads on ISS structure because, you know, when you deploy it from a collapsed to an expanded state, there is some loads that's imparted back to ISS. We had to make sure that those loads were within ISS margins. So that-- and there are several other safety considerations, you know. Flam-- flame resistance was another big safety consideration because the module was-- the module was completely nonmetallic and full of fabrics. Host: That's right. Rajib Dasgupta: Off-gassing was another consideration because, again, the module was completely-- then external contamination was another consideration. All those-- all those-- big, big safety items were really what we worked on to protect ISS. But at the same time, we tried to make sure that the technology demonstration of the BEAM module was done in an acceptable manner. Right? Host: But it also seems like the idea of protecting ISS ultimately benefits the module itself, right? This idea of making sure that it's, you know, that-- that it's going to have this many loads, it's not going to impact the structure of the International Space Station. That could be translated to another BEAM project or the idea of making sure the fabrics are flame resistant. Again, flames in space not good, so it's perfectly translatable to their own technologies. Rajib Dasgupta: Absolutely, absolutely. So, these are considerations that, you know, long-term could be used in, you know, expandable technology, further development of expandable technology, let's say for exploration or something. These are the same considerations we have for deep space exploration. Host: Yeah, yeah, right. So, taking the same technologies, going further out, even-- I'm sure there's discussions of expandable technologies on-- for planetary bodies too and surfaces that have microgravity environment. Rajib Dasgupta: Right. Host: Yeah. So, perfectly translatable. Rajib Dasgupta: Yep. Host: So, how about the journey of BEAM? Where was it constructed and all the way its journey up to the International Space Station? Rajib Dasgupta: So, BEAM was constructed over at Bigelow Aerospace facility at Las Vegas, Nevada. And then, once it was fully done, the flight module was fully done, it was shipped over to the Kennedy Space Center launch complex 40 annex where the Falcon 9 and Dragon launches. But first it was there in the SpaceX cargo processing facility where we did a lot of the integration work. The final integration work and the sensor work and cleaning-- we did final cleaning of the module and then put it inside the trunk. OK? So, way-- the way Dragon integration works, they integrate the payload inside the trunk separately and then once the payload is integrated inside the trunk, then the trunk goes and gets integrated on the rest of the Dragon capsule and then one step ahead then the Dragon capsule gets integrated into Falcon 9. So, it takes place in steps. Host: OK. Rajib Dasgupta: So, we first integrated the payload onto the trunk. That was our job. And once we finished that, we came back. And then the SpaceX team took it from there and integrated it into the launch vehicle. Host: Was it expanded on the ground at any point during this process? Rajib Dasgupta: No. Host: So, it was always in this packed configuration. Rajib Dasgupta: It was always in-- the flight module was always in the packed configuration, yes. Host: OK, so test modules I guess-- Rajib Dasgupta: Test modules and qualification test modules were expanded on the ground. Host: OK. Very cool. Host: So, then they launched-- was it April 2015? Rajib Dasgupta: Yeah, actually the exact date was April eighth of 2016. Host: Twenty-sixteen, OK. Rajib Dasgupta: The BEAM was launched and it reached ISS on April 10th of 2016. Dragon, of course, has a two-day journey to ISS, 48-hour. And then the Dragon got to port to ISS and sat there for a little while. It's normal, OK? And then on May 28th is when-- well, in May, beginning-- middle of May is when we started expanding BEAM. OK? We took it out from the Dragon trunk robotically with the ISS-- the space station arm. And then brought it on its final home on Node-3 aft. And then, after that, we started deploying it or expanding it. And, finally, we got it deployed on May 28th, 2016. Host: OK. Rajib Dasgupta: To be exact. But we had some challenges during expansion. Host: I see. What were those challenges? Rajib Dasgupta: Well, it was not opening up. As simple as that. Host: Yeah. Rajib Dasgupta: Yeah. And basically-- again, to protect ISS from a load standpoint, the procedures we had was not to open those inflation tanks initially because that would impact-- impart a lot of impact loads on ISS. So, the procedures we had was to slowly inject ISS through the IMV, the inter-module ventilation valve to expand BEAM. But I guess we were injecting so little air into it, it was not-- and coupled with the fact that-- it-- the flight BEAM was sitting in that packed configuration for almost a year-- Host: Oh, right. Rajib Dasgupta: And the fact also that we were introducing so little air, that was not enough to overcome the stiction between the layers. Imagine if you have several layers of fabric pressed onto each other and sitting there for year or two, you know, they'll have some stiction in there and that was the whole problem. It was not separating. So, finally we-- the mission team, you know, was very smart enough to develop some alternate procedures where they would introduce a larger amount of air to have a little bit force to expand and slowly and slowly BEAM surely expanded. Host: So, then how did everything perform? What was the-- what were some of the-- Rajib Dasgupta: Oh, immaculately. Host: Really? Rajib Dasgupta: Yeah. Once we expanded BEAM, everything performed really well. The crew went in there and we introduced ISS air, we started exchanging ISS air. It was clean and there was no fault or anything like that. Everything was fine. Everything-- in my opinion, everything behaved as it was-- as it was designed. That was a really good, good story for Bigelow Aerospace because I think they did a good job in designing the whole thing. Host: That's a great feeling too when you work on something for so long and you open-- you know, you see the crew members opening the hatch and everything's exactly how you expected. Rajib Dasgupta: Right. The only thing is it didn't expand initially-- Host: That's true. Rajib Dasgupta: Because the original design was made to be expanded with those inflation tanks and we didn't use it because of safety reasons, of course. ISS safety reasons. But-- so, there was a little bit of trial and error in the expansion. Once it expanded, it behaved like it was designed. Totally. Host: So, BEAM has its own inflation tanks that it-- Rajib Dasgupta: Eight. Eight of those tanks. Host: OK. And that would be used if it wasn't attached to the International Space Station? It could basically expand on itself? Rajib Dasgupta: It could. But even on BEAM while attached to station, the whole idea was to expand it to its full shape with ISS air at minimal pressure and then you release those tank airs to expand it to its full pressure. Host: I see. OK. Rajib Dasgupta: So, first with ISS air slowly expanding it to its shape. At that point, there would be literally no pressure. Very little pressure inside the module. And then, once it's fully-- attains its shape, in other words, the forward to aft bulkhead has its full separation per design in the expanded state, then you release those air tanks and fully pressurize BEAM. Host: OK. Very cool. What inside-- inside, were there experiments, I guess, to-- you know, like you said, this is a technology demonstration, so what were some of the things in the planning phase to test the technology? What equipment was used? Rajib Dasgupta: Well, primarily we had four different kinds of sensors. One was-- one primary set of sensors was measuring the radiation environment inside BEAM. The other two set of-- one-- another set of sensor was there to measure the deployment loads. In other words, how much load the BEAM bulkhead got imparted when it was deploying. So, obviously that sensor was not required after deployment. That was just to collect the deployment data. And then another one was-- is-- the sensor is to generate orbital debris data. Debris. Micrometeoroid orbital debris impacts. Now, interestingly enough, BEAM is in a position on ISS where the debris environment is pretty benign, so we don't expect to get a lot of debris hits, but the researchers still found this data interesting. So, we put that sensor in there and then there were some thermal sensors also to measure the temperature environment inside. Host: That's right. Rajib Dasgupta: So, essentially, everything to characterize the structure and the radiation environment. Structure and radiation environment. Host: That's interesting about the micrometeoroid impacts. I wouldn't have thought about it before, but like you said, it's on the aft end, the back end of the Space Station. So, you've got the Node-3 is right in the way of all the stuff. OK. Rajib Dasgupta: It has its own natural shielding from Node-3. That's right. Host: OK, but you're still getting pretty good data then, right? Rajib Dasgupta: Yes. I believe we are getting very good data and performance of BEAM overall has been very, very good. I mean from a condensation or, you know, regular structural integrity standpoint, it's been very, very good. And, actually, Jay-- you know from Gerald Valle that ISS has decided to extend BEAM's life. Host: That's right. Rajib Dasgupta: Beyond its two-year operation life. Host: That's right. Nice little foreshadowing there because we're about to talk to Gerard next. So, this is pretty cool. All right. So, thanks so much for coming on Rajib. I just wanted to-- before I kind of wrap up, I wanted to say, you know, what-- I wanted to ask what was-- how long were you with the BEAM project before you moved on to this new role? Rajib Dasgupta: You know, I was there-- I was the first to be employed with BEAM or work with BEAM and so I was there right from April 2010 when the first proposal came. So, I was leading that whole feasibility assessment effort and everything and then I saw it until pretty much deployment and on-orbit operation. So-- Host: All right. Rajib Dasgupta: So, I pretty much followed the project through until it got installed in ISS and started operating safely. Host: So, you saw the whole thing then, right? Rajib Dasgupta: Yeah, basically I saw the whole thing. Yeah. Host: All right. Well, hey, you're the perfect person to have on this, right, because you saw the whole history of it. So, I really appreciate you coming on today. Next, we'll talk to Gerard about some of the current projects and, like you foreshadowed, some of the future of BEAM. So, again, Rajib, thank you so much. Rajib Dasgupta: Yeah, thanks. Host: All right. Gerard, thanks for coming on the show today. I'm glad we could actually make the time to talk about BEAM, especially-- so, we just had a conversation with Rajib Dasgupta about the history, but now you're the current project manager, right? Gerard Valle: Correct. Host: But you've been a part of, you know, BEAM for a while. You started as a structures lead, right? Gerard Valle: Yes, struct and mech system manager. Host: OK. Very cool. All right. So, why don't we-- since Rajib kind of covered the history of BEAM and kind of where it started and all the way through its deployment, why don't we start with just what is BEAM because I don't think we've kind of covered that quite yet. Gerard Valle: Yeah, so Bigelow-- I mean BEAM stands for Bigelow Expandable Activity Module. It's basically an expandable module, also sometimes called inflatable, but it has currently birthed to Node-3 aft on ISS. It was launched on a SpaceX Falcon 9 rocket back in April of 2016 and it was birthed and deployed in May of 2016 and it's currently a technology demonstration, you know, experiment with a two-year certified life. And there's currently an effort to extend the life of BEAM to the end of ISS life as well as utilize BEAM as a stowage module. Host: Oh, wow. OK. Lots going on. So, after it was deployed, it kind of went through a couple of these tests, right, where it was-- the whole point of BEAM was as kind of a test module, right, to kind of test this technology. Gerard Valle: Right. So, when they first put it on orbit they, you know, did leak checks and made sure that it checked out fine and then the crew ingressed and they spent a couple days putting in a suite of sensors, you know, that can measure temperature, you know, pressure, they can measure micrometeoroid orbital debris impacts, thermal temperatures I think I mentioned already, and then also radiation. So, radiation performance. Host: Very good. Is some of the data being analyzed right now or do you have some kind of oversight of how it performs right now? Gerard Valle: Yes. We basically get periodic data reports. The crew ingresses periodic and goes in and grabs some of the data. It gets downlinked and then we process a lot of that data and then we produce quarterly reports that get sent back to NASA headquarters. Host: Oh, nice. So, it's still going on then. How long is-- how long will the astronauts be doing that? Gerard Valle: So, it's got a two-year certified life, so the plan was to go through probably May, June of 2018, but then ISS has shown an interest of actually-- you know, they're running into some stowage, you know, potential stowage issues come up with some new racks coming on board, so they're looking for a little additional space and they're looking at utilizing BEAM to offload some of the stowage, you know, constraints. And so, yeah, we're currently looking at that and then once that happens, then we'll just continue taking data, being as it's already up there and you've already got the instrumentation in place. Host: Yeah, why not? You have the two-year certified life, but then they've assessed that, yeah, it can stay there longer and serve as a great place to store things. Gerard Valle: Yep. They're currently undergoing the stress analysis and fracture and fatigue analysis to extend that life, but things actually look pretty good from the initial assessments. Host: Very cool. OK. So, when you're looking at BEAM, I mean this-- the whole concept of an expandable module is very different from the modules that are currently on the station. What are some of the essential differences between, you know, your regular module-- let's just say the Destiny-- Destiny Module-- the US laboratory and BEAM, what are the essential differences? Gerard Valle: So, the big difference is it's expandable, so, you know, it takes a lower fairing, you know, a smaller volume to launch it. So, we know this was able to be launched in the trunk of Falcon 9, you know, Dragon and, you know, then expanded to a full diameter. And so, for a long-term space mission, you can actually, you know, launch a larger core and then expand that to a much larger module. So, really it's the expandable portion and then, you know, most of your-- like your Destiny model module is made out of metallic structure, all metallic for the most part, and then BEAM actually has a metallic, you know, portion as well as fabric structure, you know, so that helps with the expansion. Host: All right. OK, cool. So, is it-- is the expandable module lighter? Is it kind of the same weight? Is it-- I'm imagining since it's smaller, it must be lighter, right? Gerard Valle: Well, once you expand it, you know, it, you know, becomes much larger. The micrometeoroid orbital debris protection system, that's usually one of your more heavy, you know, layers, because, you know, it's-- you know, you have the same requirement. And so, you know, you're not seeing great mass savings. What you do see is mass over volume-- Host: I see. Gerard Valle: You know, savings, and so you can basically launch a smaller volume and then get bigger once you're on orbit and so your mass and volume ratios are better than your traditional, you know, aluminum modules. Host: There you go. So, it's not just this fabric module that expands in space. There are layers. There are intricate layers in this module, right? Gerard Valle: Absolutely. So, I can't really, you know, talk about the BEAM layers as they're, you know, proprietary, what I can talk about is like TransHab, you know, BEAM was-- as Rajib mentioned was based off of TransHab and TransHab had a shell construction, you know, with a variety of layers. So, there's an inner layer to protect the bladder. The bladder keeps the gas in. There's a structural restraint layer, which is kind of like the leather of a football. I mean high strength, of course, you see much higher loads. Host: Oh yeah. Gerard Valle: And then, of course you have your micrometeoroid orbital debris layers, which are offset, and then of course you have your thermal protection layers, which are passive-- you know, it's a passive thermal protection system. And then, finally, for low-Earth orbit, you have the outermost layer, which is the atomic oxygen protection layer. Host: OK. All right. So, each layer has a very, very specific purpose, right? Gerard Valle: Yeah, we actually looked at trying to combine some of these layers-- Host: Oh yeah. Gerard Valle: And it-- you know, it-- there were inefficiencies. So, I think, yeah, they each have to serve their purpose and serve them well. Host: There you go. OK. So, I mean one of the main things about being an expandable module is the expansion itself. So, how does an expandable module expand? Like how did BEAM expand? Gerard Valle: So, it's, you know, relatively straightforward. You basically, you know, you release it so, you know, it has some type of, you know, restraint system that keeps it from expanding, you know, during an ascent. Once you get on orbit, you basically cut those restraints and so now it's free to expand and then you just start putting gas in, which in this case is air, breathable air, and then of course that-- the air, you know, creates the pressure inside and that, you know, drives it out until it finally takes its final shape. Host: Interesting. OK. So-- and that happened once it was actually attached on the station, right? You attached it first and then started pumping air into it. Gerard Valle: Yep, exactly. Host: OK. Very cool. So, inside, once it actually-- once it actually expanded-- I don't remember-- I believe-- was it Jeff Williams was the first crew member to enter the BEAM? Gerard Valle: I believe so. Host: Yeah, he said it was a little bit chilly, which he's a native Wisconsin, so obviously he was able to take it pretty easy, but inside, was it-- what was revealed once he actually went inside? What's the inside structure look like? Gerard Valle: So, you can see the inner liner, you know, obviously that's, you know, the bulk of the structure, but then you also have the metallic bulkheads, the fore and aft, and then of course there's a stabilization structure going between fore and aft and so you can see those four bars going between the two bulkheads. And of course, you know, at the back towards the aft portion, they had all the pressurization tanks, like scuba tanks, and stowage locker and basic shear panels that help carry loads during the initial launch. Host: OK. So, all of that was for launch, but do they just stay there after it's deployed, or do they serve a purpose, like, on the day to day? Gerard Valle: So, a lot of that hardware has since been removed. The pressurization tanks, the little stowage locker-- most of the big stuff to make way for the stowage that I mentioned earlier. Host: Yeah, yeah, yeah. OK. So, that's-- so, that's-- OK. They've kind of cleared this out so you can actually stow it. How-- is there a plan for how things are going to be stowed? Are you going to use, like, elastic straps or-- I mean because-- and the inside is just like this open shell, right? Gerard Valle: Sure. Well, there's-- I mentioned there are some bars that kind of go between the fore and aft bulkheads and so you can actually tie to those bars. So, they have what they call M1 and M3 bags and so they're already actually have them in place empty, tied into BEAM on the outer portion and then the crew can still ingress in the middle and then of course start putting stuff inside those bags. Host: OK. Very cool. All right. So, the whole-- again, to reiterate, BEAM is a test. You know, they were testing this technology on the space station because it was a great place to do so, right? The space station provided power, provided air to actually test the structure of BEAM, this experiment module, right? So, what are-- so, you kind of already alluded to some of the tests that were going on, but what did that process look like? Did-- were they constantly taking readings or was it more like, you know, check everything and then close the door? Gerard Valle: Well, I mean, they initially did the initial checks and so that took a little while and then they closed the door and then they go back in every, you know, two to three months and then pull data. They do microbial swabs, air sampling, and so, you know, that's all, you know, great. The, you know, the radiation they had some, you know, passive little, you know, sensors that just stay on BEAM and so they have to go in there and take them back to the ground. They have other ones that look like a little thumb drive and those are more active and those are always on and measuring and so you can actually download that data but in real time you have to downlink it and then process it. And then as well as the temperature data, that-- they, you know, download that as well and downlink it. And then of course the impact detection system, you know, that is a more complex process where they actually downlink that data and then some NASA engineers out at Langley process that data and they were able to triangulate and tell where, you know, the module got impacted, whether it was inside or outside and the amount of energy that they expect, you know, hit the module. Host: OK. And they're still analyzing that or they finding some things that maybe they want to change for the next BEAM or the next expandable module? Gerard Valle: Yeah, they're-- it's-- like I say, it's an ongoing effort and we plan to keep it going once we extend the life and make it a stowage module. Host: OK. Were some of these instruments taken up on BEAM and then once it expanded they just kind of stayed there, or was it more of the astronauts came in and started placing these things around and what parts of BEAM actually? Gerard Valle: So, there was a-- on the aft bulkhead, which the whole thing was compressed when it started, and so they had some accelerometers that they put on the aft bulkhead and so during inflation they can actually measure how it accelerated during expansion. All of the other sensors were set up separately and the crew went in and then outfitted the module once it was fully expanded and pressurized. Host: OK. So, right now it's-- I'm trying to imagine where it is on station. You said the aft bulkhead. It's actually attached to the aft side-- the back-facing side of Node-3. Is that right? Gerard Valle: Yeah, Node-3 aft, correct. Host: Yeah, and that's where the exercise equipment is, that's kind of where the Cupola is. They've got another storage module there actually right now, the PMM, right? Gerard Valle: Yeah, so they actually have to move the ARED out of the way to ingress into BEAM. Host: Oh, really? Gerard Valle: Yeah, so that's part of the ingress, you know, plan. Host: Oh, OK. Cool. So, would it be-- the ingress plan, does that mean-- does that mean ARED is going to have to be moved every time they want to enter BEAM or store something or are things going to be kind of shifted around? Gerard Valle: No, that's the nominal plan. They move ARED before they go into BEAM. Host: Oh, every time? OK. OK. So, it's kind of like long-term storage then, right? It wouldn't be any kind of short-term thing? Gerard Valle: Correct. Host: Yeah. OK, that makes a lot of sense. OK. So, now BEAM is kind of-- you said about to wrap up its testing. We're looking at kind of a mid-2018 timeframe, but then, you know, you said it's going to stay there and be a storage facility for-- on the International Space Station. Is there-- is there an end date to that or will it be kind of as long as possible? Gerard Valle: Yeah, exactly. It's as long as possible. So, obviously once you-- once you, you know, put everything in there, you'd like to leave it there as long as you can. So, the ideal goal is through the end of station life and it'll be dependent on the analysis that comes back from Bigelow Aerospace. Host: All right. Very cool. All right. So, the point of-- again, to reiterate-- the point of BEAM is a test. It's to take a look at expandable technology and see what else can we do with it. And I know there are some plans, right, because this is a-- this is a technology that was originally developed at NASA and licensed by Bigelow, correct? Gerard Valle: Correct. Host: OK. So, they have plans for this expandable tech. What's-- what are they looking to do? Gerard Valle: So, the big thing on their-- or near-term thing on their, you know, plans is the B330. So, BEAM is about 16 cubic meters. The B330 is 330 cubic meters, so much larger, you know, multiple, you know, levels. So, it's really, you know, exciting. It's basically the similar size to what the original TransHab design was. And then, of course, they're looking at all different-- a lot of different options for the B330. Possibly putting one on the International Space Station. It has a precursor for other mission-- advanced exploration missions, as well as looking at it for lunar surface, cislunar, as well as Mars and transit to Mars. Host: Wow. I mean I imagine that's-- even when it's not expanded, that still has to be a pretty heavy thing to launch into space. What kind of vehicle would take that up? Gerard Valle: I mean, you know, you could use any shuttle class, so like anything that's as big as a shuttle. So, you know, the, you know, the SLS could take it up, actually could bring it up on the smaller SLS. The Block 1, Block 2, and then of course if you have larger vehicles then, you know, that, you know, makes things even easier or you have alternate vehicles or modules you can launch. Host: Very cool. So, you can attach part of it to the International Space Station, there's a chance for it to be somewhere in low-Earth orbit, but then there's planetary versions too. You can actually design an expandable module for a planetary surface then or like a lunar surface? Gerard Valle: Absolutely. Host: Ah, very cool. Gerard Valle: Yeah, so there's actually-- as part of the next step, they're actually looking at, you know, utilization on ISS and utilization on the lunar surface and how the different architectures. At the Bigelow Aerospace website, they actually show, you know, lunar, you know, multiple modules on the lunar surface. Host: OK. Very cool. And there's-- yeah, no, there's a-- definitely a case for having this expandable technology as a habitat that can go on the lunar surface or Mars, but have you worked with some designs in the past and-- because you said you were working with TransHab as well too, right? Gerard Valle: Sure. I was the shell lead back during TransHab and then of course I worked other, you know, smaller modules, helping develop that technology throughout the years. So, it's been a big part of my career and a lot of fun and interesting and it's very exciting to see a private company, you know, utilize it and launch multiple modules. The Genesis modules back in '06 and '07, you know, summer of '06 and '07. And then, of course, to be a part of BEAM and actually see it, you know, launched and utilized on the International Space Station is very excited-- very exciting. And I'm especially excited about B330 because I would just love to see a module of that scale, you know, on the International Space Station or, you know, any of these other architectures that we've discussed. Host: Yeah. A giant expandable module with multiple floors-- I don't know what you would call it, multiple layers, multiple levels-- that's pretty cool to actually work on something like that. So, as the-- as the-- you said the shell lead. Is this the outer-- were you focusing on a single layer when you were working on that structure or were you kind of doing the whole outside, I guess? Gerard Valle: Yeah, it was for all of the fabric structure. So, everything from the inner liner that I described-- bladder, restraint layer, MMOD, thermal protection system, you know, as well as the atomic oxygen layer for low-Earth orbit. Host: OK. Has a lot of the technology kind of remained the same or has there-- has there been significant improvements as you've been working on it over time? Gerard Valle: Well, you know, NASA has done, you know, some improvements, but really, you know, Bigelow Aerospace, they've invested, you know, quite a bit of money and improved a lot of areas and so-- I mean they're-- they've actually made it a, you know, a flight-proven, you know, man-rated TRL 9 system. So, yes, absolutely lots of improvements and great work out there at Bigelow Aerospace. Host: Very cool. Is there any plans for NASA to use expandable technology? I mean-- I guess either working with Bigelow, because you said maybe Bigelow can develop something and then NASA can purchase that service, but is there any work on the NASA end? Gerard Valle: So, I think NASA's still in the evaluation stage. You know, I know they have that next step that I mentioned earlier and so, you know, there's Bigelow Aerospace as well as other private companies that are looking at expandable technology and so they're gathering data and seeing where it best fits in the architectures, but there's no firm plans, like, you know, plan to put an inflatable on, you know, the lunar surface right now, but there's still-- it's still in the trade space, so that's exciting. Host: Very cool. So, how about the relationship between NASA and Bigelow? I'm trying to understand just-- so, you're working-- you're the project manager for BEAM right now and working with Bigelow, is it on a daily basis? Are they-- are you working with their engineers or how does that relationship work? Gerard Valle: Yeah, we have a biweekly meeting, you know, for-- we call it a biweekly, you know, it's a technology meeting between Bigelow and NASA as well as all the different areas. And so, you know, we work down and in-between those meetings we'll have, you know, off-- especially with the stowage module, we'll meet with them-- you know, a lot of it's just emails or tele-- phone calls and stuff, but there's a lot going on and so, yeah, we'll meet with them periodically and, you know, good engineers and good people to work with for the last, you know, several years. Host: Very cool. Where is-- where's Bigelow based out of where they're working on some of this technology? Gerard Valle: They're North Las Vegas is where their base is. Host: OK. Very cool. Do you travel out there sometimes or is it mostly telecons? Gerard Valle: Not as much lately. It's mostly telecons and sometimes they come up here, but during the actual design and development, you know, I was out there a little bit more and so it was, you know, exciting to see their facilities and the actual module come and, you know, come and developing and being built and inspected and tested. So, you know, that was great. Host: Very cool. Do they-- do they manufacture all of the tech-- all of the layers and all of the parts of the-- of Bigelow expandable module there in Las Vegas or is it-- are the parts brought together somewhere else? Gerard Valle: Yeah, that I'm not 100% sure. I know they do a lot there, but I'm sure they outsource some things as well. Host: Yeah, definitely. I didn't know if-- is-- are some of the layers I guess NASA technology? Is any of it developed here and then shipped out to Vegas? Gerard Valle: No, no. They're definitely a fully independent company and so they're doing their own thing. You know, we will, you know, work with them if we see something that we, you know, think is a little risk or have a concern and so we'll talk to them about that and have meetings and splinter-- and work together and then of course, like I say, they're great at solving problems. So, you know, we've had a great experience working with them over the last few years. Host: Fantastic. Very exciting to see, you know, the success of BEAM so far and the fact that, yeah, let's keep this-- let's keep this activity module there and just use it as storage and then to hear some of the plans going forward and the possibilities of this expandable tech is pretty cool. So, Gerard, I really wanted to thank you for coming on the podcast today. Gerard Valle: Yeah, thank you. Good. Host: Yeah, this is a nice overview of BEAM and thanks again to Rajib for coming on and kind of describing the history, kind of getting the full picture of this whole story of expandable tech. So, again, I appreciate you coming on and wish you the best of luck for the remainder of BEAM's test up through the middle of the year. Gerard Valle: Great. Thanks. [ Music ] Host: Hey, thanks for sticking around. So, today we talked about the Bigelow Expandable Activity Module with Gerard Valle and Rajib Dasgupta. A little bit about the history all the way through the potential future of expandable modules in space. Pretty cool stuff. If you want to know more about Bigelow Expandable Activity Module, you can go to nasa.gov/iss to get some of the latest updates on how that is working on the International Space Station. It's right now, as Gerard said, being used as sort of a storage module and going to be on the ISS for the long haul, which is pretty cool. You can also see some updates on the International Space Station Facebook, Twitter, and Instagram, just use the #askNASA on your favorite platform to submit an idea or ask a question or maybe submit a suggestion for an episode of the podcast, just like Max with an exclamation point did for this episode. Other podcasts, you can also check out other NASA podcasts like Gravity Assist hosted by Dr. Jim Green that talks about planetary science or you can talk about NASA in Silicon Valley hosted by our friends over at Ames Research Center that talk about a lot of other components on the International Space Station and are doing some pretty cool stuff on Twitch TV. So, this podcast was recorded on February eighth and February 20th. Thanks to Alex Perryman, Dan Huot, Steve Munday, Pat Ryan, Bill Stafford and Kelly Humphries. Thanks again to Rajib Dasgupta and Gerard Valle for coming on the show. We'll be back next week.

Infectious diseases of marine molluscs and host responses as revealed by genomic tools

PubMed Central

Ford, Susan E.

2016-01-01

More and more infectious diseases affect marine molluscs. Some diseases have impacted commercial species including MSX and Dermo of the eastern oyster, QPX of hard clams, withering syndrome of abalone and ostreid herpesvirus 1 (OsHV-1) infections of many molluscs. Although the exact transmission mechanisms are not well understood, human activities and associated environmental changes often correlate with increased disease prevalence. For instance, hatcheries and large-scale aquaculture create high host densities, which, along with increasing ocean temperature, might have contributed to OsHV-1 epizootics in scallops and oysters. A key to understanding linkages between the environment and disease is to understand how the environment affects the host immune system. Although we might be tempted to downplay the role of immunity in invertebrates, recent advances in genomics have provided insights into host and parasite genomes and revealed surprisingly sophisticated innate immune systems in molluscs. All major innate immune pathways are found in molluscs with many immune receptors, regulators and effectors expanded. The expanded gene families provide great diversity and complexity in innate immune response, which may be key to mollusc's defence against diverse pathogens in the absence of adaptive immunity. Further advances in host and parasite genomics should improve our understanding of genetic variation in parasite virulence and host disease resistance. PMID:26880838

Sarcocystis calchasi has an expanded host range and induces neurological disease in cockatiels (Nymphicus hollandicus) and North American rock pigeons (Columbia livia f. dom.).

PubMed

Olias, Philipp; Maier, Kristina; Wuenschmann, Arno; Reed, Leslie; Armién, Aníbal G; Shaw, Daniel P; Gruber, Achim D; Lierz, Michael

2014-02-24

Pigeon protozoal encephalitis (PPE) is an emerging central nervous system disease of pigeons (Columba livia f. domestica) caused by the apicomplexan parasite Sarcocystis calchasi. The intermediate host specificity of S. calchasi had been considered high, as domestic chickens were resistant to experimental infection. Here, we have re-evaluated this concept and expanded the known host range of S. calchasi by experimental infection of cockatiels (Nymphicus hollandicus), a species distantly related to pigeons. In this work, a group of eight cockatiels were experimentally infected with S. calchasi, which resulted in a biphasic central nervous system disease that paralleled PPE in many aspects, albeit with a more diverse pathology. All cockatiels became lethargic and polyuric between days 7 and 13 pi and during that time schizonts of S. calchasi were found primarily in the liver and spleen accompanied by necrosis and inflammation. As with pigeons, neurological signs occurred during a chronic phase of the disease in three cockatiels between 57 and 63 dpi. However, all five cockatiels necropsied in that period, or at the end of the trial at 76 dpi, had a severe lymphohistiocytic and necrotizing encephalitis. No tissue cysts were found in the heart, and cockatiels infected with 10(5) sporocysts only had a negligible parasite load in skeletal muscles despite the presence of severe central nervous system lesions. Notably, intralesional schizonts were identified in the brain of one cockatiel. In contrast to previous results, intralesional schizonts were also identified in the brains of three of six naturally infected pigeons from Minnesota and Missouri examined as part of an epidemiological investigation. In both the cockatiel and the pigeons, tissue cysts were found concurrently with schizonts suggesting an uncommon phenomenon in the Sarcocystis life cycle. Based on the results of this study, transmission of S. calchasi to avian species other than the domestic pigeon is possible. These findings suggest a, so far, unmonitored prevalence of S. calchasi in avian populations and highlight a possible ongoing dissemination of this parasite in the Northern Hemisphere. Copyright © 2013 Elsevier B.V. All rights reserved.

Alarmins and immunity.

PubMed

Yang, De; Han, Zhen; Oppenheim, Joost J

2017-11-01

More than a decade has passed since the conceptualization of the "alarmin" hypothesis. The alarmin family has been expanding in terms of both number and the concept. It has recently become clear that alarmins play important roles as initiators and participants in a diverse range of physiological and pathophysiological processes such as host defense, regulation of gene expression, cellular homeostasis, wound healing, inflammation, allergy, autoimmunity, and oncogenesis. Here, we provide a general view on the participation of alarmins in the induction of innate and adaptive immune responses, as well as their contribution to tumor immunity. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Chlorite dissolution kinetics at pH 3–10 and temperature to 275°C

DOE PAGES

Smith, Megan M.; Carroll, Susan A.

2015-12-02

Sheet silicates and clays are ubiquitous in geothermal environments. Their dissolution is of interest because this process contributes to scaling reactions along fluid pathways and alteration of fracture surfaces which could affect reservoir permeability. Here, in order to better predict the geochemical impacts on long-term performance of engineered geothermal systems, we have measured chlorite dissolution and developed a generalized kinetic rate law applicable over an expanded range of solution pH and temperature. Chlorite, (Mg,Al,Fe) 12(Si,Al) 8O 20(OH) 16, commonly occurs in many geothermal host rocks as either a primary mineral or alteration product.

Chlorite dissolution kinetics at pH 3–10 and temperature to 275°C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Megan M.; Carroll, Susan A.

Sheet silicates and clays are ubiquitous in geothermal environments. Their dissolution is of interest because this process contributes to scaling reactions along fluid pathways and alteration of fracture surfaces which could affect reservoir permeability. Here, in order to better predict the geochemical impacts on long-term performance of engineered geothermal systems, we have measured chlorite dissolution and developed a generalized kinetic rate law applicable over an expanded range of solution pH and temperature. Chlorite, (Mg,Al,Fe) 12(Si,Al) 8O 20(OH) 16, commonly occurs in many geothermal host rocks as either a primary mineral or alteration product.

Factors affecting host range in a generalist seed pathogen of semi-arid shrublands

Treesearch

Julie Beckstead; Susan E. Meyer; Kurt O. Reinhart; Kellene M. Bergen; Sandra R. Holden; Heather F. Boekweg

2014-01-01

Generalist pathogens can exhibit differential success on different hosts, resulting in complex host range patterns. Several factors operate to reduce realized host range relative to potential host range, particularly under field conditions. We explored factors influencing host range of the naturally occurring generalist ascomycete grass seed pathogen Pyrenophora...

Patterns of cowbird parasitism in the Southern Atlantic Coastal Plain and Piedmont.

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.C. Kilgo; C.E. Moorman

2003-09-01

Until recently, little information was available on patterns of brood parasitism by Brownheaded Cowbirds (Molothrus ater) in the southeastern United States, a region into which cowbirds expanded their range only during the last half of the Twentieth Century and where their abundance is relatively low. We compiled parasitism data from several published and unpublished studies conducted in Georgia and South Carolina from 1993-2000 to examine levels of brood parasitism and determine frequent host species. The combined dataset included 1,372 nests of 24 species reported in the literature to have been parasitized by cowbirds. The parasitism rate on all species combinedmore » was 8.2%. Considering only those species that served as hosts in these studies (n = I2), the parasitism rate was 9.3%. Seven species were parasitized at rates 2 10%. Based on the extent of parasitism (among studies and locations), their relative abundance, and the sample size of nests, Prairie Warblers (Dendroicta discolor), Hooded Warblers (Wilsonia citrina), Yellow-breasted Chats (Icteria virens), and Indigo Buntings (Passerina cyanea), all shrub nesters, appear to be the most important cowbird hosts in the region. Parasitism on some species reported as frequent hosts elsewhere was extremely low or not documented. We conclude that the impact of brood parasitism on the seasonal fecundity of hosts in the region probably is minimal, but additional work is warranted on species of concern, such as the Painted Bunting (Passerina ciris).« less

Poxviruses and the Evolution of Host Range and Virulence

PubMed Central

Haller, Sherry L.; Peng, Chen; McFadden, Grant; Rothenburg, Stefan

2013-01-01

Poxviruses as a group can infect a large number of animals. However, at the level of individual viruses, even closely related poxviruses display highly diverse host ranges and virulence. For example, variola virus, the causative agent of smallpox, is human-specific and highly virulent only to humans, whereas related cowpox viruses naturally infect a broad spectrum of animals and only cause relatively mild disease in humans. The successful replication of poxviruses depends on their effective manipulation of the host antiviral responses, at the cellular-, tissue- and species-specific levels, which constitutes a molecular basis for differences in poxvirus host range and virulence. A number of poxvirus genes have been identified that possess host range function in experimental settings, and many of these host range genes target specific antiviral host pathways. Herein, we review the biology of poxviruses with a focus on host range, zoonotic infections, virulence, genomics and host range genes as well as the current knowledge about the function of poxvirus host range factors and how their interaction with the host innate immune system contributes to poxvirus host range and virulence. We further discuss the evolution of host range and virulence in poxviruses as well as host switches and potential poxvirus threats for human and animal health. PMID:24161410

Mapping brucellosis increases relative to elk density using hierarchical Bayesian models

USGS Publications Warehouse

Cross, Paul C.; Heisey, Dennis M.; Scurlock, Brandon M.; Edwards, William H.; Brennan, Angela; Ebinger, Michael R.

2010-01-01

The relationship between host density and parasite transmission is central to the effectiveness of many disease management strategies. Few studies, however, have empirically estimated this relationship particularly in large mammals. We applied hierarchical Bayesian methods to a 19-year dataset of over 6400 brucellosis tests of adult female elk (Cervus elaphus) in northwestern Wyoming. Management captures that occurred from January to March were over two times more likely to be seropositive than hunted elk that were killed in September to December, while accounting for site and year effects. Areas with supplemental feeding grounds for elk had higher seroprevalence in 1991 than other regions, but by 2009 many areas distant from the feeding grounds were of comparable seroprevalence. The increases in brucellosis seroprevalence were correlated with elk densities at the elk management unit, or hunt area, scale (mean 2070 km2; range = [95–10237]). The data, however, could not differentiate among linear and non-linear effects of host density. Therefore, control efforts that focus on reducing elk densities at a broad spatial scale were only weakly supported. Additional research on how a few, large groups within a region may be driving disease dynamics is needed for more targeted and effective management interventions. Brucellosis appears to be expanding its range into new regions and elk populations, which is likely to further complicate the United States brucellosis eradication program. This study is an example of how the dynamics of host populations can affect their ability to serve as disease reservoirs.

The lodgepole × jack pine hybrid zone in Alberta, Canada: a stepping stone for the mountain pine beetle on its journey East across the boreal forest?

PubMed

Lusebrink, Inka; Erbilgin, Nadir; Evenden, Maya L

2013-09-01

Historical data show that outbreaks of the tree killing mountain pine beetle are often preceded by periods of drought. Global climate change impacts drought frequency and severity and is implicated in the range expansion of the mountain pine beetle into formerly unsuitable habitats. Its expanded range has recently reached the lodgepole × jack pine hybrid zone in central Alberta, Canada, which could act as a transition from its historical lodgepole pine host to a jack pine host present in the boreal forest. This field study tested the effects of water limitation on chemical defenses of mature trees against mountain pine beetle-associated microorganisms and on beetle brood success in lodgepole × jack pine hybrid trees. Tree chemical defenses as measured by monoterpene emission from tree boles and monoterpene concentration in needles were greater in trees that experienced water deficit compared to well-watered trees. Myrcene was identified as specific defensive compound, since it significantly increased upon inoculation with dead mountain pine beetles. Beetles reared in bolts from trees that experienced water deficit emerged with a higher fat content, demonstrating for the first time experimentally that drought conditions benefit mountain pine beetles. Further, our study demonstrated that volatile chemical emission from tree boles and phloem chemistry place the hybrid tree chemotype in-between lodgepole pine and jack pine, which might facilitate the host shift from lodgepole pine to jack pine.

Host mitochondrial association evolved in the human parasite Toxoplasma gondii via neofunctionalization of a gene duplicate

USDA-ARS?s Scientific Manuscript database

In Toxoplasma gondii, an intracellular parasite of humans and other warm-blooded animals, the ability to associate with host mitochondria (HMA) is driven by a locally expanded gene family that encodes multiple mitochondrial association factor 1 (MAF1) proteins. The importance of copy number in the e...

Assessment of Navel Oranges, Clementine Tangerines, and Rutaceous Fruits as Hosts of Bactrocera cucurbitae and Bactrocera latifrons (Diptera: Tephritidae)

PubMed Central

McQuate, Grant T.; Follett, Peter A.; Liquido, Nicanor J.; Sylva, Charmaine D.

2015-01-01

Export of Citrus spp. fruits may require risk mitigation measures if grown in areas with established tephritid fruit fly (Diptera: Tephritidae) populations capable of infesting the fruits. The host status of Citrus spp. fruits is unclear for two tephritid fruit fly species whose geographic ranges have expanded in recent years: melon fly, Bactrocera cucurbitae (Cocquillett), and Bactrocera latifrons (Hendel). In no choice cage infestation studies, B. latifrons oviposited into intact and punctured Washington navel oranges (Citrus sinensis [L.] Osbeck) and Clementine tangerines (C. reticulata L. var. Clementine), but eggs rarely developed to the adult stage. B. cucurbitae readily infested intact and punctured tangerines, and to a lesser extent punctured oranges, but did not infest intact oranges. Limited cage infestation and only a single literature report of field Citrus spp. infestation suggest that risk mitigation of Citrus spp. for B. latifrons is not needed. Risk mitigation options of Citrus spp. for B. cucurbitae, including heat and cold treatments and systems approaches, are discussed. PMID:26816484

Design and Test of an Event Detector for the ReflectoActive Seals System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stinson, Brad J

2006-05-01

The purpose of this thesis was to research, design, develop and test a novel instrument for detecting fiber optic loop continuity and spatially locating fiber optic breaches. The work is for an active seal system called ReflectoActive Seals whose purpose is to provide real time container tamper indication. A Field Programmable Gate Array was used to implement a loop continuity detector and a spatial breach locator based on a high acquisition speed single photon counting optical time domain reflectometer. Communication and other control features were added in order to create a usable instrument that met defined requirements. A host graphicalmore » user interface was developed to illustrate system use and performance. The resulting device meets performance specifications by exhibiting a dynamic range of 27dB and a spatial resolution of 1.5 ft. The communication scheme used expands installation options and allows the device to communicate to a central host via existing Local Area Networks and/or the Internet.« less

Design and Test of an Event Detector and Locator for the ReflectoActive Seals System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stinson, Brad J

2006-06-01

The purpose of this work was to research, design, develop and test a novel instrument for detecting fiber optic loop continuity and spatially locating fiber optic breaches. The work is for an active seal system called ReflectoActive{trademark} Seals whose purpose is to provide real time container tamper indication. A Field Programmable Gate Array was used to implement a loop continuity detector and a spatial breach locator based on a high acquisition speed single photon counting optical time domain reflectometer. Communication and other control features were added in order to create a usable instrument that met defined requirements. A host graphicalmore » user interface was developed to illustrate system use and performance. The resulting device meets performance specifications by exhibiting a dynamic range of 27dB and a spatial resolution of 1.5 ft. The communication scheme used expands installation options and allows the device to communicate to a central host via existing Local Area Networks and/or the Internet.« less

Immunity to intestinal pathogens: lessons learned from Salmonella

PubMed Central

McSorley, Stephen J.

2014-01-01

Summary Salmonella are a common source of food or water-borne infection and cause a wide range of clinical disease in human and animal hosts. Salmonella are relatively easy to culture and manipulate in a laboratory setting, and the infection of laboratory animals induces robust innate and adaptive immune responses. Thus, immunologists have frequently turned to Salmonella infection models to expand understanding of immunity to intestinal pathogens. In this review, I summarize current knowledge of innate and adaptive immunity to Salmonella and highlight features of this response that have emerged from recent studies. These include the heterogeneity of the antigen-specific T-cell response to intestinal infection, the prominence of microbial mechanisms to impede T and B-cell responses, and the contribution of non-cognate pathways for elicitation of T-cell effector functions. Together, these different issues challenge an overly simplistic view of host-pathogen interaction during mucosal infection but also allow deeper insight into the real-world dynamic of protective immunity to intestinal pathogens. PMID:24942689

Metabolic engineering of yeast for lignocellulosic biofuel production.

PubMed

Jin, Yong-Su; Cate, Jamie Hd

2017-12-01

Production of biofuels from lignocellulosic biomass remains an unsolved challenge in industrial biotechnology. Efforts to use yeast for conversion face the question of which host organism to use, counterbalancing the ease of genetic manipulation with the promise of robust industrial phenotypes. Saccharomyces cerevisiae remains the premier host for metabolic engineering of biofuel pathways, due to its many genetic, systems and synthetic biology tools. Numerous engineering strategies for expanding substrate ranges and diversifying products of S. cerevisiae have been developed. Other yeasts generally lack these tools, yet harbor superior phenotypes that could be exploited in the harsh processes required for lignocellulosic biofuel production. These include thermotolerance, resistance to toxic compounds generated during plant biomass deconstruction, and wider carbon consumption capabilities. Although promising, these yeasts have yet to be widely exploited. By contrast, oleaginous yeasts such as Yarrowia lipolytica capable of producing high titers of lipids are rapidly advancing in terms of the tools available for their metabolic manipulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Wildlife health in a rapidly changing North: focus on avian disease

USGS Publications Warehouse

Van Hemert, Caroline R.; Pearce, John M.; Handel, Colleen M.

2014-01-01

Climate-related environmental changes have increasingly been linked to emerging infectious diseases in wildlife. The Arctic is facing a major ecological transition that is expected to substantially affect animal and human health. Changes in phenology or environmental conditions that result from climate warming may promote novel species assemblages as host and pathogen ranges expand to previously unoccupied areas. Recent evidence from the Arctic and subarctic suggests an increase in the spread and prevalence of some wildlife diseases, but baseline data necessary to detect and verify such changes are still lacking. Wild birds are undergoing rapid shifts in distribution and have been implicated in the spread of wildlife and zoonotic diseases. Here, we review evidence of current and projected changes in the abundance and distribution of avian diseases and outline strategies for future research. We discuss relevant climatic and environmental factors, emerging host–pathogen contact zones, the relationship between host condition and immune function, and potential wildlife and human health outcomes in northern regions.

Acute bee paralysis virus occurs in the Asian honey bee Apis cerana and parasitic mite Tropilaelaps mercedesae.

PubMed

Chanpanitkitchote, Pichaya; Chen, Yanping; Evans, Jay D; Li, Wenfeng; Li, Jianghong; Hamilton, Michele; Chantawannakul, Panuwan

2018-01-01

Viruses, and especially RNA viruses, constantly change and adapt to new host species and vectors, posing a potential threat of new and reemerging infectious diseases. Honey bee Acute bee paralysis virus (ABPV) and Deformed wing virus (DWV) are two of the most common honey bee viruses found in European honey bees Apis mellifera and have been implicated in worldwide Varroa-associated bee colony losses. Previous studies have shown that DWV has jumped hosts several times in history causing infection in multiple host species. In the present study, we show that DWV infection could be detected in the Asian honey bee, A. cerana, and the parasitic mite Tropilaelaps mercedesae, confirming previous findings that DWV is a multi-host pathogen and supporting the notion that the high prevalence of DWV in honey bee host populations could be attributed to the high adaptability of this virus. Furthermore, our study provides the first evidence that ABPV occurs in both A. cerana and T. mercedesae in northern Thailand. The geographical proximity of host species likely played an important role in the initial exposure and the subsequent cross-species transmission of these viruses. Phylogenetic analyses suggest that ABPV might have moved from T. mercedesae to A. mellifera and to A. cerana while DWV might have moved in the opposite direction from A. cerana to A. mellifera and T. mercedesae. This result may reflect the differences in virus life history and virus-host interactions, warranting further investigation of virus transmission, epidemiology, and impacts of virus infections in the new hosts. The results from this study indicate that viral populations will continue to evolve and likely continue to expand host range, increasing the need for effective surveillance and control of virus infections in honey bee populations. Copyright © 2017 Elsevier Inc. All rights reserved.

A review of the flea genus Phalacropsylla Rothschild, 1915 (Siphonaptera, Ctenophthalmidae, Neopsyllinae, Phalacropsyllini) with new host and distributional records

PubMed Central

Acosta, Roxana; Hastriter, Michael W.

2017-01-01

Abstract A redescription of the genus Phalacropsylla Rothschild is provided. Six species are recognized: Phalacropsylla allos Wagner, P. hamata Tipton and Mendez, P. morlani Eads and Campos, P. nivalis Barrera and Traub, P. oregonensis Lewis and Maser, and P. paradisea Rothschild. Phalacropsylla hamata is designated herein as a junior synonym of P. paradisea. The distribution of P. paradisea is more extensive than previously thought, extending from Arizona through southern Colorado, into New Mexico, Texas, and northern Mexico (State of Nuevo León). It is the least host-specific of all species of Phalacropsylla, occurring on 13 different host species including cricetid, heteromyid, murid, and sciurid rodents and several carnivores, although it most commonly occurs on Neotoma albigula Hartley. The range of P. oregonensis is expanded from eastern Oregon to southeastern Idaho. Numerous records are documented for the most common and ubiquitous species, P. allos, which is found in British Columbia, central to northern California, Idaho, Montana, Colorado, Nevada, Utah, Wyoming, Arizona, and New Mexico. Neotoma cinerea Ord is the principal host of P. allos. Phalacropsylla allos is a winter flea west of the Rocky Mountains, but it has been reported in warmer months of the year on the eastern slopes of the Rocky Mountains in Larimer County, Colorado. A distribution map and key are provided for all species in the genus Phalacropsylla. PMID:28769677

A novel experimental system using the liverwort Marchantia polymorpha and its fungal endophytes reveals diverse and context-dependent effects.

PubMed

Nelson, Jessica M; Hauser, Duncan A; Hinson, Rosemary; Shaw, A Jonathan

2018-05-01

Fungal symbioses are ubiquitous in plants, but their effects have mostly been studied in seed plants. This study aimed to assess the diversity of fungal endophyte effects in a bryophyte and identify factors contributing to the variability of outcomes in these interactions. Fungal endophyte cultures and axenic liverwort clones were isolated from wild populations of the liverwort, Marchantia polymorpha. These collections were combined in a gnotobiotic system to test the effects of fungal isolates on the growth rates of hosts under laboratory conditions. Under the experimental conditions, fungi isolated from M. polymorpha ranged from aggressively pathogenic to strongly growth-promoting, but the majority of isolates caused no detectable change in host growth. Growth promotion by selected fungi depended on nutrient concentrations and was inhibited by coinoculation with multiple fungi. The M. polymorpha endophyte system expands the resources for this model liverwort. The experiments presented here demonstrate a wealth of diversity in fungal interactions even in a host reported to lack standard mycorrhizal symbiosis. In addition, they show that some known pathogens of vascular plants live in M. polymorpha and can confer benefits to this nonvascular host. This highlights the importance of studying endophyte effects across the plant tree of life. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Diverse styles of submarine venting on the ultra-slow spreading Mid-Cayman Rise (Invited)

NASA Astrophysics Data System (ADS)

German, C. R.; Bowen, A.; Coleman, M. L.; Honig, D. L.; Huber, J. A.; Jakuba, M.; Kinsey, J. C.; Kurz, M. D.; Leroy, S.; McDermott, J.; Mercier de Lepinay, B. F.; Nakamura, K.; Seewald, J.; Smith, J.; Sylva, S.; van Dover, C. L.; Whitcomb, L. L.; Yoerger, D. R.

2010-12-01

Thirty years after the first discovery of high-temperature submarine venting, the vast majority of the global Mid Ocean Ridge remains unexplored for hydrothermal activity. Of particular interest are the world’s ultra-slow spreading ridges which were the last to be demonstrated to host high-temperature venting, but may host systems particularly relevant to pre-biotic chemistry and the origins of life. Here we report first evidence for diverse and very deep hydrothermal vents along the ~110 km long, ultra-slow spreading Mid-Cayman Rise collected using a combination of CTD-rosette operations and dives of the Hybrid Remotely Operated Vehicle (HROV) Nereus in 2009 followed by shore based work-up of samples for geochemical and microbiological analyses. Our data indicate that the Mid-Cayman Rise hosts at least three discrete hydrothermal sites, each representing a different type of water-rock interaction, including both mafic and ultra-mafic systems and, at ~5000 m, the deepest known hydrothermal vent. Although submarine hydrothermal circulation, in which seawater percolates through and reacts with host lithologies, occurs on all mid-ocean ridges, the diversity of vent-types identified here and their relative geographic isolation make the Mid-Cayman Rise unique in the oceans. These new sites offer prospects for: an expanded range of vent-fluid compositions; varieties of abiotic organic chemical synthesis and extremophile microorganisms; and unparalleled faunal biodiversity - all in close proximity.

A review of the flea genus Phalacropsylla Rothschild, 1915 (Siphonaptera, Ctenophthalmidae, Neopsyllinae, Phalacropsyllini) with new host and distributional records.

PubMed

Acosta, Roxana; Hastriter, Michael W

2017-01-01

A redescription of the genus Phalacropsylla Rothschild is provided. Six species are recognized: Phalacropsylla allos Wagner, P. hamata Tipton and Mendez, P. morlani Eads and Campos, P. nivalis Barrera and Traub, P. oregonensis Lewis and Maser, and P. paradisea Rothschild. Phalacropsylla hamata is designated herein as a junior synonym of P. paradisea . The distribution of P. paradisea is more extensive than previously thought, extending from Arizona through southern Colorado, into New Mexico, Texas, and northern Mexico (State of Nuevo León). It is the least host-specific of all species of Phalacropsylla , occurring on 13 different host species including cricetid, heteromyid, murid, and sciurid rodents and several carnivores, although it most commonly occurs on Neotoma albigula Hartley. The range of P. oregonensis is expanded from eastern Oregon to southeastern Idaho. Numerous records are documented for the most common and ubiquitous species, P. allos , which is found in British Columbia, central to northern California, Idaho, Montana, Colorado, Nevada, Utah, Wyoming, Arizona, and New Mexico. Neotoma cinerea Ord is the principal host of P. allos . Phalacropsylla allos is a winter flea west of the Rocky Mountains, but it has been reported in warmer months of the year on the eastern slopes of the Rocky Mountains in Larimer County, Colorado. A distribution map and key are provided for all species in the genus Phalacropsylla .

Poxvirus Host Range Genes and Virus–Host Spectrum: A Critical Review

PubMed Central

Oliveira, Graziele Pereira; Rodrigues, Rodrigo Araújo Lima; Lima, Maurício Teixeira; Drumond, Betânia Paiva; Abrahão, Jônatas Santos

2017-01-01

The Poxviridae family is comprised of double-stranded DNA viruses belonging to nucleocytoplasmic large DNA viruses (NCLDV). Among the NCLDV, poxviruses exhibit the widest known host range, which is likely observed because this viral family has been more heavily investigated. However, relative to each member of the Poxviridae family, the spectrum of the host is variable, where certain viruses can infect a large range of hosts, while others are restricted to only one host species. It has been suggested that the variability in host spectrum among poxviruses is linked with the presence or absence of some host range genes. Would it be possible to extrapolate the restriction of viral replication in a specific cell lineage to an animal, a far more complex organism? In this study, we compare and discuss the relationship between the host range of poxvirus species and the abundance/diversity of host range genes. We analyzed the sequences of 38 previously identified and putative homologs of poxvirus host range genes, and updated these data with deposited sequences of new poxvirus genomes. Overall, the term host range genes might not be the most appropriate for these genes, since no correlation between them and the viruses’ host spectrum was observed, and a change in nomenclature should be considered. Finally, we analyzed the evolutionary history of these genes, and reaffirmed the occurrence of horizontal gene transfer (HGT) for certain elements, as previously suggested. Considering the data presented in this study, it is not possible to associate the diversity of host range factors with the amount of hosts of known poxviruses, and this traditional nomenclature creates misunderstandings. PMID:29112165

The effect of climate change on skin disease in North America.

PubMed

Kaffenberger, Benjamin H; Shetlar, David; Norton, Scott A; Rosenbach, Misha

2017-01-01

Global temperatures continue to rise, reaching new records almost every year this decade. Although the causes are debated, climate change is a reality. Consequences of climate change include melting of the arctic ice cap, rising of sea levels, changes in precipitation patterns, and increased severe weather events. This article updates dermatologists about the effects of climate change on the epidemiology and geographic ranges of selected skin diseases in North America. Although globalization, travel, and trade are also important to changing disease and vector patterns, climate change creates favorable habitats and expanded access to immunologically naïve hosts. Endemic North American illnesses such as Lyme disease, leishmaniasis, and dimorphic fungal infections have recently expanded the geographic areas of risk. As temperatures increase, epidemic viral diseases such as hand-foot-and-mouth disease may develop transmission seasons that are longer and more intense. Chikungunya and dengue are now reported within the southern United States, with Zika on the horizon. Cutaneous injuries from aquatic and marine organisms that have expanding habitats and longer durations of peak activity include jellyfish envenomation, cercarial dermatitis, and seabather eruption, among others. Skin cancer rates may also be affected indirectly by changes in temperature and associated behaviors. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

MTOR-Driven Metabolic Reprogramming Regulates Legionella pneumophila Intracellular Niche Homeostasis

PubMed Central

Abshire, Camille F.; Roy, Craig R.

2016-01-01

Vacuolar bacterial pathogens are sheltered within unique membrane-bound organelles that expand over time to support bacterial replication. These compartments sequester bacterial molecules away from host cytosolic immunosurveillance pathways that induce antimicrobial responses. The mechanisms by which the human pulmonary pathogen Legionella pneumophila maintains niche homeostasis are poorly understood. We uncovered that the Legionella-containing vacuole (LCV) required a sustained supply of host lipids during expansion. Lipids shortage resulted in LCV rupture and initiation of a host cell death response, whereas excess of host lipids increased LCVs size and housing capacity. We found that lipids uptake from serum and de novo lipogenesis are distinct redundant supply mechanisms for membrane biogenesis in Legionella-infected macrophages. During infection, the metabolic checkpoint kinase Mechanistic Target of Rapamycin (MTOR) controlled lipogenesis through the Serum Response Element Binding Protein 1 and 2 (SREBP1/2) transcription factors. In Legionella-infected macrophages a host-driven response that required the Toll-like receptors (TLRs) adaptor protein Myeloid differentiation primary response gene 88 (Myd88) dampened MTOR signaling which in turn destabilized LCVs under serum starvation. Inactivation of the host MTOR-suppression pathway revealed that L. pneumophila sustained MTOR signaling throughout its intracellular infection cycle by a process that required the upstream regulator Phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and one or more Dot/Icm effector proteins. Legionella-sustained MTOR signaling facilitated LCV expansion and inhibition of the PI3K-MTOR-SREPB1/2 axis through pharmacological or genetic interference or by activation of the host MTOR-suppression response destabilized expanding LCVs, which in turn triggered cell death of infected macrophages. Our work identified a host metabolic requirement for LCV homeostasis and demonstrated that L. pneumophila has evolved to manipulate MTOR-dependent lipogenesis for optimal intracellular replication. PMID:27942021

Opportunistic Pathogenic Yeasts

NASA Astrophysics Data System (ADS)

Banerjee, Uma

Advances in medical research, made during the last few decades, have improved the prophylactic, diagnostic and therapeutic capabilities for variety of infections/diseases. However, many of the prophylactic and therapeutic procedures have been seen in many instances to exact a price of host-vulnerability to an expanding group of opportunistic pathogens and yeasts are one of the important members in it. Fortunately amongst the vast majority of yeasts present in nature only few are considered to have the capability to cause infections when certain opportunities predisposes and these are termed as ‘opportunistic pathogenic yeasts.’ However, the term ‘pathogenic’ is quite tricky, as it depends of various factors of the host, the ‘bug’ and the environment to manifest the clinical infection. The borderline is expanding. In the present century with unprecedented increase in number of immune-compromised host in various disciplines of health care settings, where any yeast, which has the capability to grow at 37 ° C (normal body temperature of human), can be pathogenic and cause infection in particular situation

Extended studies of Baltomyces styrax in Idaho and expanded distribution of this isopod gut fungus in USA.

PubMed

Oman, Sarah J; White, Merlin M

2012-01-01

Trichomycetes or gut fungi are currently considered to be an ecological group consisting of both fungi and protists that inhabit the guts of arthropods from varied environments. Baltomyces styrax has been included as a member of the Asellariales, a small and understudied order of true gut fungi. Baltomyces styrax has remained monotypic and not been reported formally since it was first described by Cafaro in 1999 from one collection in Louisiana. Herein we report on subsequent collections of this fungus, from both lentic and lotic locations, over the past several years from four other states, most recently Idaho, where we have records over a 4 y span. We repeatedly collected at one lentic site in Idaho for 5 mo, which allowed an extended study of not only the life history of B. styrax but also the discovery of morphological characteristics that were not reported earlier. Therefore we are emending the species description and providing additional information on the ecology and host range of B. styrax as well as providing a context for comparison to Asellaria, the type genus of the Asellariales. We also extend the known host range and suggest that the fungus is much more widespread than current records indicate.

The Genome of the Generalist Plant Pathogen Fusarium avenaceum Is Enriched with Genes Involved in Redox, Signaling and Secondary Metabolism

PubMed Central

Lysøe, Erik; Harris, Linda J.; Walkowiak, Sean; Subramaniam, Rajagopal; Divon, Hege H.; Riiser, Even S.; Llorens, Carlos; Gabaldón, Toni; Kistler, H. Corby; Jonkers, Wilfried; Kolseth, Anna-Karin; Nielsen, Kristian F.; Thrane, Ulf; Frandsen, Rasmus J. N.

2014-01-01

Fusarium avenaceum is a fungus commonly isolated from soil and associated with a wide range of host plants. We present here three genome sequences of F. avenaceum, one isolated from barley in Finland and two from spring and winter wheat in Canada. The sizes of the three genomes range from 41.6–43.1 MB, with 13217–13445 predicted protein-coding genes. Whole-genome analysis showed that the three genomes are highly syntenic, and share>95% gene orthologs. Comparative analysis to other sequenced Fusaria shows that F. avenaceum has a very large potential for producing secondary metabolites, with between 75 and 80 key enzymes belonging to the polyketide, non-ribosomal peptide, terpene, alkaloid and indole-diterpene synthase classes. In addition to known metabolites from F. avenaceum, fuscofusarin and JM-47 were detected for the first time in this species. Many protein families are expanded in F. avenaceum, such as transcription factors, and proteins involved in redox reactions and signal transduction, suggesting evolutionary adaptation to a diverse and cosmopolitan ecology. We found that 20% of all predicted proteins were considered to be secreted, supporting a life in the extracellular space during interaction with plant hosts. PMID:25409087

Diversifying selection in the wheat stem rust fungus acts predominantly on pathogen-associated gene families and reveals candidate effectors

PubMed Central

Sperschneider, Jana; Ying, Hua; Dodds, Peter N.; Gardiner, Donald M.; Upadhyaya, Narayana M.; Singh, Karam B.; Manners, John M.; Taylor, Jennifer M.

2014-01-01

Plant pathogens cause severe losses to crop plants and threaten global food production. One striking example is the wheat stem rust fungus, Puccinia graminis f. sp. tritici, which can rapidly evolve new virulent pathotypes in response to resistant host lines. Like several other filamentous fungal and oomycete plant pathogens, its genome features expanded gene families that have been implicated in host-pathogen interactions, possibly encoding effector proteins that interact directly with target host defense proteins. Previous efforts to understand virulence largely relied on the prediction of secreted, small and cysteine-rich proteins as candidate effectors and thus delivered an overwhelming number of candidates. Here, we implement an alternative analysis strategy that uses the signal of adaptive evolution as a line of evidence for effector function, combined with comparative information and expression data. We demonstrate that in planta up-regulated genes that are rapidly evolving are found almost exclusively in pathogen-associated gene families, affirming the impact of host-pathogen co-evolution on genome structure and the adaptive diversification of specialized gene families. In particular, we predict 42 effector candidates that are conserved only across pathogens, induced during infection and rapidly evolving. One of our top candidates has recently been shown to induce genotype-specific hypersensitive cell death in wheat. This shows that comparative genomics incorporating the evolutionary signal of adaptation is powerful for predicting effector candidates for laboratory verification. Our system can be applied to a wide range of pathogens and will give insight into host-pathogen dynamics, ultimately leading to progress in strategies for disease control. PMID:25225496

Exciton-to-Dopant Energy Transfer in Mn-Doped Cesium Lead Halide Perovskite Nanocrystals.

PubMed

Parobek, David; Roman, Benjamin J; Dong, Yitong; Jin, Ho; Lee, Elbert; Sheldon, Matthew; Son, Dong Hee

2016-12-14

We report the one-pot synthesis of colloidal Mn-doped cesium lead halide (CsPbX 3 ) perovskite nanocrystals and efficient intraparticle energy transfer between the exciton and dopant ions resulting in intense sensitized Mn luminescence. Mn-doped CsPbCl 3 and CsPb(Cl/Br) 3 nanocrystals maintained the same lattice structure and crystallinity as their undoped counterparts with nearly identical lattice parameters at ∼0.2% doping concentrations and no signature of phase separation. The strong sensitized luminescence from d-d transition of Mn 2+ ions upon band-edge excitation of the CsPbX 3 host is indicative of sufficiently strong exchange coupling between the charge carriers of the host and dopant d electrons mediating the energy transfer, essential for obtaining unique properties of magnetically doped quantum dots. Highly homogeneous spectral characteristics of Mn luminescence from an ensemble of Mn-doped CsPbX 3 nanocrystals and well-defined electron paramagnetic resonance spectra of Mn 2+ in host CsPbX 3 nanocrystal lattices suggest relatively uniform doping sites, likely from substitutional doping at Pb 2+ . These observations indicate that CsPbX 3 nanocrystals, possessing many superior optical and electronic characteristics, can be utilized as a new platform for magnetically doped quantum dots expanding the range of optical, electronic, and magnetic functionality.

Novel application of species richness estimators to predict the host range of parasites.

PubMed

Watson, David M; Milner, Kirsty V; Leigh, Andrea

2017-01-01

Host range is a critical life history trait of parasites, influencing prevalence, virulence and ultimately determining their distributional extent. Current approaches to measure host range are sensitive to sampling effort, the number of known hosts increasing with more records. Here, we develop a novel application of results-based stopping rules to determine how many hosts should be sampled to yield stable estimates of the number of primary hosts within regions, then use species richness estimation to predict host ranges of parasites across their distributional ranges. We selected three mistletoe species (hemiparasitic plants in the Loranthaceae) to evaluate our approach: a strict host specialist (Amyema lucasii, dependent on a single host species), an intermediate species (Amyema quandang, dependent on hosts in one genus) and a generalist (Lysiana exocarpi, dependent on many genera across multiple families), comparing results from geographically-stratified surveys against known host lists derived from herbarium specimens. The results-based stopping rule (stop sampling bioregion once observed host richness exceeds 80% of the host richness predicted using the Abundance-based Coverage Estimator) worked well for most bioregions studied, being satisfied after three to six sampling plots (each representing 25 host trees) but was unreliable in those bioregions with high host richness or high proportions of rare hosts. Although generating stable predictions of host range with minimal variation among six estimators trialled, distribution-wide estimates fell well short of the number of hosts known from herbarium records. This mismatch, coupled with the discovery of nine previously unrecorded mistletoe-host combinations, further demonstrates the limited ecological relevance of simple host-parasite lists. By collecting estimates of host range of constrained completeness, our approach maximises sampling efficiency while generating comparable estimates of the number of primary hosts, with broad applicability to many host-parasite systems. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

The need for a national LIDAR dataset

USGS Publications Warehouse

Stoker, Jason M.; Harding, David; Parrish, Jay

2008-01-01

On May 21st and 22nd 2008, the U.S. Geological Survey (USGS), the National Aeronautics and Space Administration (NASA), and the Association of American State Geologists (AASG) hosted the Second National Light Detection and Ranging (Lidar) Initiative Strategy Meeting at USGS Headquarters in Reston, Virginia. The USGS is taking the lead in cooperation with many partners to design and implement a future high-resolution National Lidar Dataset. Initial work is focused on determining viability, developing requirements and specifi cations, establishing what types of information contained in a lidar signal are most important, and identifying key stakeholders and their respective roles. In February 2007, USGS hosted the fi rst National Lidar Initiative Strategy Meeting at USGS Headquarters in Virginia. The presentations and a published summary report from the fi rst meeting can be found on the Center for Lidar Information Coordination and Knowledge (CLICK) Website: http://lidar.cr.usgs.gov. The fi rst meeting demonstrated the public need for consistent lidar data at the national scale. The goals of the second meeting were to further expand on the ideas and information developed in the fi rst meeting, to bring more stakeholders together, to both refi ne and expand on the requirements and capabilities needed, and to discuss an organizational and funding approach for an initiative of this magnitude. The approximately 200 participants represented Federal, State, local, commercial and academic interests. The second meeting included a public solicitation for presentations and posters to better democratize the workshop. All of the oral presentation abstracts that were submitted were accepted, and the 25 poster submissions augmented and expanded upon the oral presentations. The presentations from this second meeting, including audio, can be found on CLICK at http://lidar.cr.usgs.gov/national_lidar_2008.php. Based on the presentations and the discussion sessions, the following points were emphasized throughout the meeting

Neutrophils: Between Host Defence, Immune Modulation, and Tissue Injury

PubMed Central

Kruger, Philipp; Saffarzadeh, Mona; Weber, Alexander N. R.; Rieber, Nikolaus; Radsak, Markus; von Bernuth, Horst; Benarafa, Charaf; Roos, Dirk; Skokowa, Julia; Hartl, Dominik

2015-01-01

Neutrophils, the most abundant human immune cells, are rapidly recruited to sites of infection, where they fulfill their life-saving antimicrobial functions. While traditionally regarded as short-lived phagocytes, recent findings on long-term survival, neutrophil extracellular trap (NET) formation, heterogeneity and plasticity, suppressive functions, and tissue injury have expanded our understanding of their diverse role in infection and inflammation. This review summarises our current understanding of neutrophils in host-pathogen interactions and disease involvement, illustrating the versatility and plasticity of the neutrophil, moving between host defence, immune modulation, and tissue damage. PMID:25764063

Mixture-amount design and response surface modeling to assess the effects of flavonoids and phenolic acids on developmental performance of Anastrepha ludens.

PubMed

Pascacio-Villafán, Carlos; Lapointe, Stephen; Williams, Trevor; Sivinski, John; Niedz, Randall; Aluja, Martín

2014-03-01

Host plant resistance to insect attack and expansion of insect pests to novel hosts may to be modulated by phenolic compounds in host plants. Many studies have evaluated the role of phenolics in host plant resistance and the effect of phenolics on herbivore performance, but few studies have tested the joint effect of several compounds. Here, we used mixture-amount experimental design and response surface modeling to study the effects of a variety of phenolic compounds on the development and survival of Mexican fruit fly (Anastrepha ludens [Loew]), a notorious polyphagous pest of fruit crops that is likely to expand its distribution range under climate change scenarios. (+)- Catechin, phloridzin, rutin, chlorogenic acid, and p-coumaric acid were added individually or in mixtures at different concentrations to a laboratory diet used to rear individuals of A. ludens. No effect was observed with any mixture or concentration on percent pupation, pupal weight, adult emergence, or survival from neonate larvae to adults. Larval weight, larval and pupal developmental time, and the prevalence of adult deformities were affected by particular mixtures and concentrations of the compounds tested. We suggest that some combinations/concentrations of phenolic compounds could contribute to the management of A. ludens. We also highlight the importance of testing mixtures of plant secondary compounds when exploring their effects upon insect herbivore performance, and we show that mixture-amount design is a useful tool for this type of experiments.

Accelerated Genome Engineering through Multiplexing

PubMed Central

Zhao, Huimin

2015-01-01

Throughout the biological sciences, the past fifteen years have seen a push towards the analysis and engineering of biological systems at the organism level. Given the complexity of even the simplest organisms, though, to elicit a phenotype of interest often requires genotypic manipulation of several loci. By traditional means, sequential editing of genomic targets requires a significant investment of time and labor, as the desired editing event typically occurs at a very low frequency against an overwhelming unedited background. In recent years, the development of a suite of new techniques has greatly increased editing efficiency, opening up the possibility for multiple editing events to occur in parallel. Termed as multiplexed genome engineering, this approach to genome editing has greatly expanded the scope of possible genome manipulations in diverse hosts, ranging from bacteria to human cells. The enabling technologies for multiplexed genome engineering include oligonucleotide-based and nuclease-based methodologies, and their application has led to the great breadth of successful examples described in this review. While many technical challenges remain, there also exists a multiplicity of opportunities in this rapidly expanding field. PMID:26394307

Common but different: The expanding realm of Cladosporium

PubMed Central

Bensch, K.; Groenewald, J.Z.; Braun, U.; Dijksterhuis, J.; de Jesús Yáñez-Morales, M.; Crous, P.W.

2015-01-01

The genus Cladosporium (Cladosporiaceae, Dothideomycetes), which represents one of the largest genera of dematiaceous hyphomycetes, has been intensively investigated during the past decade. In the process, three major species complexes (C. cladosporioides, C. herbarum and C. sphaerospermum) were resolved based on morphology and DNA phylogeny, and a monographic revision of the genus (s. lat.) published reflecting the current taxonomic status quo. In the present study a further 19 new species are described based on phylogenetic characters (nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, as well as partial actin and translation elongation factor 1-α gene sequences) and morphological differences. For a selection of the species with ornamented conidia, scanning electron microscopic photos were prepared to illustrate the different types of surface ornamentation. Surprisingly, during this study Cladosporium ramotenellum was found to be a quite common saprobic species, being widely distributed and occurring on various substrates. Therefore, an emended species description is provided. Furthermore, the host range and distribution data for several previously described species are also expanded. PMID:26955200

Diversity of dsDNA Viruses in a South African Hot Spring Assessed by Metagenomics and Microscopy.

PubMed

Zablocki, Olivier; van Zyl, Leonardo Joaquim; Kirby, Bronwyn; Trindade, Marla

2017-11-18

The current view of virus diversity in terrestrial hot springs is limited to a few sampling sites. To expand our current understanding of hot spring viral community diversity, this study aimed to investigate the first African hot spring (Brandvlei hot spring; 60 °C, pH 5.7) by means of electron microscopy and sequencing of the virus fraction. Microscopy analysis revealed a mixture of regular- and 'jumbo'-sized tailed morphotypes ( Caudovirales ), lemon-shaped virions ( Fuselloviridae- like; salterprovirus-like) and pleiomorphic virus-like particles. Metavirome analysis corroborated the presence of His1-like viruses and has expanded the current clade of salterproviruses using a polymerase B gene phylogeny. The most represented viral contig was to a cyanophage genome fragment, which may underline basic ecosystem functioning provided by these viruses. Furthermore, a putative Gemmata -related phage was assembled with high coverage, a previously undocumented phage-host association. This study demonstrated that a moderately thermophilic spring environment contained a highly novel pool of viruses and should encourage future characterization of a wider temperature range of hot springs throughout the world.

Is forced migration a barrier to treatment success? Similar HIV treatment outcomes among refugees and a surrounding host community in Kuala Lumpur, Malaysia.

PubMed

Mendelsohn, Joshua B; Schilperoord, Marian; Spiegel, Paul; Balasundaram, Susheela; Radhakrishnan, Anuradha; Lee, Christopher K C; Larke, Natasha; Grant, Alison D; Sondorp, Egbert; Ross, David A

2014-02-01

In response to an absence of studies among refugees and host communities accessing highly active antiretroviral therapy (HAART) in urban settings, our objective was to compare adherence and virological outcomes among clients attending a public clinic in Kuala Lumpur, Malaysia. A cross-sectional survey was conducted among adult clients (≥18 years). Data sources included a structured questionnaire that measured self-reported adherence, a pharmacy-based measure of HAART prescription refills over the previous 24 months, and HIV viral loads. The primary outcome was unsuppressed viral load (≥40 copies/mL). Among a sample of 153 refugees and 148 host community clients, refugees were younger (median age 35 [interquartile range, IQR 31, 39] vs 40 years [IQR 35, 48], p < 0.001), more likely to be female (36 vs 21 %, p = 0.004), and to have been on HAART for less time (61 [IQR 35, 108] vs 153 weeks [IQR 63, 298]; p < 0.001). Among all clients, similar proportions of refugee and host clients were <95 % adherent to pharmacy refills (26 vs 34 %, p = 0.15). When restricting to clients on treatment for ≥25 weeks, similar proportions from each group were not virologically suppressed (19 % of refugees vs 16 % of host clients, p = 0.54). Refugee status was not independently associated with the outcome (adjusted odds ratio, aOR = 1.28, 95 % CI 0.52, 3.14). Overall, the proportions of refugee and host community clients with unsuppressed viral loads and sub-optimal adherence were similar, supporting the idea that refugees in protracted asylum situations are able to sustain good treatment outcomes and should explicitly be included in the HIV strategic plans of host countries with a view to expanding access in accordance with national guidelines for HAART.

Mitochondrial genome sequencing reveals potential origins of the scabies mite Sarcoptes scabiei infesting two iconic Australian marsupials.

PubMed

Fraser, Tamieka A; Shao, Renfu; Fountain-Jones, Nicholas M; Charleston, Michael; Martin, Alynn; Whiteley, Pam; Holme, Roz; Carver, Scott; Polkinghorne, Adam

2017-11-28

Debilitating skin infestations caused by the mite, Sarcoptes scabiei, have a profound impact on human and animal health globally. In Australia, this impact is evident across different segments of Australian society, with a growing recognition that it can contribute to rapid declines of native Australian marsupials. Cross-host transmission has been suggested to play a significant role in the epidemiology and origin of mite infestations in different species but a chronic lack of genetic resources has made further inferences difficult. To investigate the origins and molecular epidemiology of S. scabiei in Australian wildlife, we sequenced the mitochondrial genomes of S. scabiei from diseased wombats (Vombatus ursinus) and koalas (Phascolarctos cinereus) spanning New South Wales, Victoria and Tasmania, and compared them with the recently sequenced mitochondrial genome sequences of S. scabiei from humans. We found unique S. scabiei haplotypes among individual wombat and koala hosts with high sequence similarity (99.1% - 100%). Phylogenetic analysis of near full-length mitochondrial genomes revealed three clades of S. scabiei (one human and two marsupial), with no apparent geographic or host species pattern, suggestive of multiple introductions. The availability of additional mitochondrial gene sequences also enabled a re-evaluation of a range of putative molecular markers of S. scabiei, revealing that cox1 is the most informative gene for molecular epidemiological investigations. Utilising this gene target, we provide additional evidence to support cross-host transmission between different animal hosts. Our results suggest a history of parasite invasion through colonisation of Australia from hosts across the globe and the potential for cross-host transmission being a common feature of the epidemiology of this neglected pathogen. If this is the case, comparable patterns may exist elsewhere in the 'New World'. This work provides a basis for expanded molecular studies into mange epidemiology in humans and animals in Australia and other geographic regions.

CRISPR–Cas9 Genetic Analysis of Virus–Host Interactions

PubMed Central

Gebre, Makda; Nomburg, Jason L.; Gewurz, Benjamin E.

2018-01-01

Clustered regularly interspaced short palindromic repeats (CRISPR) has greatly expanded the ability to genetically probe virus–host interactions. CRISPR systems enable focused or systematic, genomewide studies of nearly all aspects of a virus lifecycle. Combined with its relative ease of use and high reproducibility, CRISPR is becoming an essential tool in studies of the host factors important for viral pathogenesis. Here, we review the use of CRISPR–Cas9 for the loss-of-function analysis of host dependency factors. We focus on the use of CRISPR-pooled screens for the systematic identification of host dependency factors, particularly in Epstein–Barr virus-transformed B cells. We also discuss the use of CRISPR interference (CRISPRi) and gain-of-function CRISPR activation (CRISPRa) approaches to probe virus–host interactions. Finally, we comment on the future directions enabled by combinatorial CRISPR screens. PMID:29385696

CRISPR-Cas9 Genetic Analysis of Virus-Host Interactions.

PubMed

Gebre, Makda; Nomburg, Jason L; Gewurz, Benjamin E

2018-01-30

Clustered regularly interspaced short palindromic repeats (CRISPR) has greatly expanded the ability to genetically probe virus-host interactions. CRISPR systems enable focused or systematic, genomewide studies of nearly all aspects of a virus lifecycle. Combined with its relative ease of use and high reproducibility, CRISPR is becoming an essential tool in studies of the host factors important for viral pathogenesis. Here, we review the use of CRISPR-Cas9 for the loss-of-function analysis of host dependency factors. We focus on the use of CRISPR-pooled screens for the systematic identification of host dependency factors, particularly in Epstein-Barr virus-transformed B cells. We also discuss the use of CRISPR interference (CRISPRi) and gain-of-function CRISPR activation (CRISPRa) approaches to probe virus-host interactions. Finally, we comment on the future directions enabled by combinatorial CRISPR screens.

Successful range-expanding plants experience less above-ground and below-ground enemy impact.

PubMed

Engelkes, Tim; Morriën, Elly; Verhoeven, Koen J F; Bezemer, T Martijn; Biere, Arjen; Harvey, Jeffrey A; McIntyre, Lauren M; Tamis, Wil L M; van der Putten, Wim H

2008-12-18

Many species are currently moving to higher latitudes and altitudes. However, little is known about the factors that influence the future performance of range-expanding species in their new habitats. Here we show that range-expanding plant species from a riverine area were better defended against shoot and root enemies than were related native plant species growing in the same area. We grew fifteen plant species with and without non-coevolved polyphagous locusts and cosmopolitan, polyphagous aphids. Contrary to our expectations, the locusts performed more poorly on the range-expanding plant species than on the congeneric native plant species, whereas the aphids showed no difference. The shoot herbivores reduced the biomass of the native plants more than they did that of the congeneric range expanders. Also, the range-expanding plants developed fewer pathogenic effects in their root-zone soil than did the related native species. Current predictions forecast biodiversity loss due to limitations in the ability of species to adjust to climate warming conditions in their range. Our results strongly suggest that the plants that shift ranges towards higher latitudes and altitudes may include potential invaders, as the successful range expanders may experience less control by above-ground or below-ground enemies than the natives.

Mountain pine beetle-caused mortality over eight years in two pine hosts in mixed conifer stands of the southern Rocky Mountains

USGS Publications Warehouse

West, Daniel R.; Briggs, Jennifer S.; Jacobi, William R.; Negrón, José F.

2014-01-01

Eruptive mountain pine beetle (Dendroctonus ponderosae, MPB) populations have caused widespread mortality of pines throughout western North America since the late 1990s. Early work by A.D. Hopkins suggested that when alternate host species are available, MPB will prefer to breed in the host to which it has become adapted. In Colorado, epidemic MPB populations that originated in lodgepole pine expanded into mixed-conifer stands containing ponderosa pine, a related host. We evaluated the susceptibility of both hosts to successful MPB colonization in a survey of 19 sites in pine-dominated mixed-conifer stands spanning 140 km of the Front Range, CO, USA. In each of three 0.2-ha plots at each site, we (1) assessed trees in the annual flights of 2008–2011 to compare MPB-caused mortality between lodgepole and ponderosa pine; (2) recorded previous MPB-caused tree mortality from 2004–2007 to establish baseline mortality levels; and (3) measured characteristics of the stands (e.g. tree basal area) and sites (e.g. elevation, aspect) that might be correlated with MPB colonization. Uninfested average live basal area of lodgepole and ponderosa pine was 74% of total basal area before 2004. We found that for both species, annual percent basal area of attacked trees was greatest in one year (2009), and was lower in all other years (2004–2007, 2008, 2010, and 2011). Both pine species had similar average total mortality of 38–39% by 2011. Significant predictors of ponderosa pine mortality in a given year were basal area of uninfested ponderosa pine and the previous year’s mortality levels in both ponderosa and lodgepole pine. Lodgepole pine mortality was predicted by uninfested basal areas of both lodgepole and ponderosa pine, and the previous year’s lodgepole pine mortality. These results indicate host selection by MPB from lodgepole pine natal hosts into ponderosa pine the following year, but not the reverse. In both species, diameters of attacked trees within each year were similar, and were progressively smaller the last four years of the study period. Our results suggest that, in contrast to previous reports, ponderosa and lodgepole pine were equally susceptible to MPB infestation in the CO Front Range during our study period. This suggests that forest managers may anticipate similar impacts in both hosts during similar environmental conditions when epidemic-level MPB populations are active in mixed-pine stands.

Chapiniella variabilis (Nematoda) parasitizing Chelonoidis carbonarius and C. denticulatus (Testudinidae) in the state of Piauí.

PubMed

Freire, Simone Mousinho; Leal, Anangela Ravena da Silva; Knoff, Marcelo; Gomes, Delir Corrêa; Santos, Jeannie Nascimento Dos; Giese, Elane Guerreiro; Silva, Reinaldo José da; Mendonça, Ivete Lopes

2017-01-01

Chapiniella variabilis (Chapin, 1924), a strongylid nematode, was collected parasitizing the large intestine of the tortoises Chelonoidis carbonarius (Spix, 1824) (Cc) and C. denticulatus (Linnaeus, 1766) (Cd) in the Zoobotanical Park of the municipality of Teresina, state of Piauí, Brazil. The taxonomic identification was based on morphological and morphometric features, using bright-field and scanning electron microscopy. The present study adds new observations on the morphology, mainly relating to the mouth papillae, external and internal leaf-crown elements, excretory pore, deirids and male and female posterior end. The parasitic indices of prevalence (P), mean intensity (MI), mean abundance (MA) and range of infection (RI) of C. variabilis in these two tortoise species were: P = 100%, MI = 833.3, MA = 833.3, RI = 500-1,500 (Cc); P = 100%, MI = 472.2, MA = 472.2, RI = 333-500 (Cd). This record expands occurrences of C. variabilis to a new host, C. carbonarius, and to another state in Brazil, in the Neotropical region of South America. Adjustment to host management with the aim of improving hygiene and health conditions is suggested.

Diseases of cultured marine fishes caused by Platyhelminthes (Monogenea, Digenea, Cestoda).

PubMed

Ogawa, K

2015-01-01

Mariculture is a rapidly developing industrial sector. Generally, fish are maintained in net cages with high density. Cage culture systems allow uncontrolled flow of sea water containing potentially infectious stages of fish parasites. In such culture conditions, prevention of such parasitic infections is difficult for parasites with life cycles that complete within culture sites, among which monogeneans and blood flukes are the most important platyhelminthes. Intense monogenean infections induce respiratory and osmo-regulatory dysfunctions. A variety of control measures have been developed, including freshwater bath treatment and chemotherapy. The potential to control monogenean infections through selective breeding, modified culture techniques to avoid infection, and general fish health management are discussed. It should be noted that mariculture conditions have provided some host-specific monogeneans with a chance to expand their host ranges. Blood flukes sometimes induce mass mortality among farmed fish. In-feed administration of praziquantel is the best solution to treat infected fish. Some cases are described that show how international trade in marine fish has resulted in the spread of hitherto unknown parasites into indigenous farmed and wild fish.

Molecular tracing of white muscardine in the silkworm, Bombyx mori (Linn.) II. Silkworm white muscardine is not caused by artificial release or natural epizootic of Beauveria bassiana in China.

PubMed

Chen, Xue; Huang, Cui; He, Lingmin; Zhang, Shengli; Li, Zengzhi

2015-02-01

The fungal pathogen Beauveria bassiana causes serious economic losses in sericulture. Its origin is usually attributed to the release of B. bassiana insecticides against pine caterpillars (Dendrolimus punctuatus). In the present study, 488 B. bassiana isolates obtained from silkworm (Bombyx mori) collected from 13 Chinese provinces, and 327 B. bassiana isolates obtained from D. punctatus collected from 9 provinces, were analyzed for population genetic structure using the ISSR technique based on genetic distance. A UPGMA dendrogram clustered them into three independent clades: two B. mori clades and one D. punctatus clade. A 3-D principal component analysis further divided them into two completely independent host groups, revealing high host-specificity. This suggested that white muscardine occurring in B. mori populations throughout southern China was not caused by any B. bassiana strain either naturally prevailing in D. punctatus populations or by any strain artificially released as a fungal insecticide against D. punctatus. We further investigated the genetic differentiation coefficient Gst and gene flow between B. mori-pathogenic and D. punctatus-pathogenic B. bassiana isolates from across China and from five provinces inhabited by both B. mori and D. punctatus. The Gst value across China was computed as 0.410, while the values of the five provinces ranged from 0.508 to 0.689; all above 0.25, which is the threshold for significant genetic differentiation. This suggests that B. bassiana strains isolated from the two different hosts maintained their respective heredity without a convergent homogenization trend, and reduces the possibility that the host range of the caterpillar isolates could expand and enhance their virulence in B. mori. These findings indicate that the use of B. bassiana does not threaten the safety of sericulture. Copyright © 2014 Elsevier Inc. All rights reserved.

Irradiated and activated autologous PBMCs induce expansion of highly cytotoxic human NK cells in vitro.

PubMed

Ahn, Yong-Oon; Kim, Saerom; Kim, Tae Min; Song, Eun Young; Park, Myoung Hee; Heo, Dae Seog

2013-09-01

Adoptive cell transfer of ex vivo-activated natural killer (NK) cells is a promising therapy for cancer treatment. Because of inhibitory signaling through killer immunoglobulin-like receptor (KIR)-KIR ligands, KIR-mismatched allogeneic NK cell transfer is considered to be a more effective strategy than is autologous transfer. However, purified NK cells do not expand well enough in vitro with good manufacturing practice-compliant components for clinical use. Some investigators have developed selective expansion of NK cells from peripheral blood mononuclear cells, but these cells have the risk of graft-versus-host disease in allogeneic settings because of T cells contamination. In this study, we developed a novel method for NK cell activation and expansion. Using only good manufacturing practice-compliant components and autologous feeder cells, once purified NK cells were effectively expanded (2500-fold at day 17). The expanded cells were highly purified NK cells, and the use of these cells is suitable for allogeneic transfer without the risk of graft-versus-host disease induction. Importantly, the expanded NK cells also showed enhanced cytotoxicity compared with NK cells conventionally expanded by recombinant human interleukin 2. Finally, induction of NKG2D ligand expression on feeder cells implies that the NKG2D-NKG2DL interaction may play a role in NK cell expansion. In conclusion, this method can be used to obtain NK cells for more successful allogeneic NK cell adoptive transfer for use in antitumor immune therapy.

The quantitative theory of within-host viral evolution

NASA Astrophysics Data System (ADS)

Rouzine, Igor M.; Weinberger, Leor S.

2013-01-01

During the 1990s, a group of virologists and physicists began development of a quantitative theory to explain the rapid evolution of human immunodeficiency virus type 1 (HIV-1). This theory also proved to be instrumental in understanding the rapid emergence of drug resistance in patients. Over the past two decades, this theory expanded to account for a broad array of factors important to viral evolution and propelled development of a generalized theory applicable to a broad range of asexual and partly sexual populations with many evolving sites. Here, we discuss the conceptual and theoretical tools developed to calculate the speed and other parameters of evolution, with a particular focus on the concept of ‘clonal interference’ and its applications to untreated patients.

Vector-borne parasitic zoonoses: emerging scenarios and new perspectives.

PubMed

Colwell, Douglas D; Dantas-Torres, Filipe; Otranto, Domenico

2011-11-24

Changing climate is not the only driver for alterations in the dynamic interaction between arthropod vectors of zoonotic parasites and their hosts, including humans. A suite of other factors ranging from urbanization and deforestation to changing demographics in both developing and developed countries, the impact of the recent economic crisis, increased global movement of people and animals and follow-on effects of major catastrophes. This article reviews the most important vector-borne parasites of zoonotic concern that are changing/expanding their distribution patterns in both endemic and/or previously non-endemic areas. We include the discussion of the changing aspects of malaria, leishmaniasis, babesiosis, Chagas disease as well as of some spirurid and filarioid nematodes. Copyright © 2011. Published by Elsevier B.V.

Protease Inhibitors of Parasitic Flukes: Emerging Roles in Parasite Survival and Immune Defence.

PubMed

Ranasinghe, Shiwanthi L; McManus, Donald P

2017-05-01

Protease inhibitors play crucial roles in parasite development and survival, counteracting the potentially damaging immune responses of their vertebrate hosts. However, limited information is currently available on protease inhibitors from schistosomes and food-borne trematodes. Future characterization of these molecules is important not only to expand knowledge on parasitic fluke biology but also to determine whether they represent novel vaccine and/or drug targets. Moreover, protease inhibitors from flukes may represent lead compounds for the development of a new range of therapeutic agents against inflammatory disorders and cancer. This review discusses already identified protease inhibitors of fluke origin, emphasizing their biological function and their possible future development as new intervention targets. Copyright © 2016 Elsevier Ltd. All rights reserved.

Isolation of a novel orthobunyavirus from bat flies (Eucampsipoda africana)

PubMed Central

Palacios, Gustavo; Storm, Nadia; Markotter, Wanda; Birkhead, Monica; Kemp, Alan

2017-01-01

The Bunyaviridae family comprises viruses causing diseases of public and veterinary health importance, including viral haemorrhagic and arboviral fevers. We report the isolation, identification and genome characterization of a novel orthobunyavirus, named Wolkberg virus (WBV), from wingless bat fly ectoparasites (Eucampsipoda africana) of Egyptian fruit bats (Rousettus aegyptiacus) in South Africa. Complete genome sequence data of WBV suggests it is most closely related to two bat viruses (Mojuí dos Campos and Kaeng Khoi viruses) and an arbovirus (Nyando virus) previously shown to infect humans. WBV replicates to high titres in VeroE6 and C6-36 cells, characteristic of mosquito-borne arboviruses. These findings expand our knowledge of the diversity of orthobunyaviruses and their insect vector host range. PMID:28488954

Multipurpose end-station for coherent diffraction imaging and scattering at FERMI@Elettra free-electron laser facility.

PubMed

Capotondi, Flavio; Pedersoli, Emanuele; Bencivenga, Filippo; Manfredda, Michele; Mahne, Nicola; Raimondi, Lorenzo; Svetina, Cristian; Zangrando, Marco; Demidovich, Alexander; Nikolov, Ivaylo; Danailov, Miltcho; Masciovecchio, Claudio; Kiskinova, Maya

2015-05-01

The Diffraction and Projection Imaging (DiProI) beamline at FERMI, the Elettra free-electron laser (FEL), hosts a multi-purpose station that has been opened to users since the end of 2012. This paper describes the core capabilities of the station, designed to make use of the unique features of the FERMI-FEL for performing a wide range of static and dynamic scattering experiments. The various schemes for time-resolved experiments, employing both soft X-ray FEL and seed laser IR radiation are presented by using selected recent results. The ongoing upgrade is adding a reflection geometry setup for scattering experiments, expanding the application fields by providing both high lateral and depth resolution.

Meeting report: SMART timing--principles of single molecule techniques course at the University of Michigan 2014.

PubMed

Bartke, Rebecca M; Cameron, Elizabeth L; Cristie-David, Ajitha S; Custer, Thomas C; Denies, Maxwell S; Daher, May; Dhakal, Soma; Ghosh, Soumi; Heinicke, Laurie A; Hoff, J Damon; Hou, Qian; Kahlscheuer, Matthew L; Karslake, Joshua; Krieger, Adam G; Li, Jieming; Li, Xiang; Lund, Paul E; Vo, Nguyen N; Park, Jun; Pitchiaya, Sethuramasundaram; Rai, Victoria; Smith, David J; Suddala, Krishna C; Wang, Jiarui; Widom, Julia R; Walter, Nils G

2015-05-01

Four days after the announcement of the 2014 Nobel Prize in Chemistry for "the development of super-resolved fluorescence microscopy" based on single molecule detection, the Single Molecule Analysis in Real-Time (SMART) Center at the University of Michigan hosted a "Principles of Single Molecule Techniques 2014" course. Through a combination of plenary lectures and an Open House at the SMART Center, the course took a snapshot of a technology with an especially broad and rapidly expanding range of applications in the biomedical and materials sciences. Highlighting the continued rapid emergence of technical and scientific advances, the course underscored just how brightly the future of the single molecule field shines. © 2014 Wiley Periodicals, Inc.

Eosinophils in helminth infection: defenders and dupes

PubMed Central

Huang, Lu; Appleton, Judith A.

2016-01-01

Eosinophilia is a central feature of the host response to helminth infection. Larval stages of parasitic worms are killed in vitro by eosinophils in the presence of specific antibodies or complement. These findings established host defense as the paradigm for eosinophil function. Recently, studies in eosinophil-ablated mouse strains have revealed an expanded repertoire of immunoregulatory functions for this cell. Other reports document crucial roles for eosinophils in tissue homeostasis and metabolism, processes that are central to the establishment and maintenance of parasitic worms in their hosts. In this review, we summarize current understanding of the significance of eosinophils at the host-parasite interface, highlighting their distinct functions during primary and secondary exposure. PMID:27262918

Host preference of the vector beetle, host resistance, and expanding patterns of Japanese oak wilt in a stand

Treesearch

Kazuyoshi Futai; Hiroaki Kiku; Hong-ye Qi; Hagus Tarn; Yuko Takeuchi; Michimasa Yamasaki

2012-01-01

Since the early 1980s, an epidemic forest disease, Japanese Oak Wilt (JOW), has been spreading from coastal areas along the Sea of Japan to the interior of Honshu island and has been devastating huge areas of forests by killing an enormous number of oak trees in urban fringe mountains, gardens, and parks. The disease is caused by a fungus, Raffaelea...

Wind for Schools: Developing Educational Programs to Train a New Workforce and the Next Generation of Wind Energy Experts (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flowers, L.; Baring-Gould, I.

2010-04-01

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America's Wind for Schools project addresses these issues by: Developing Wind Application Centers (WACs) at universities; installing small wind turbines at community "host" schools; and implementing teacher training with interactive curricula at each host school.

The Mega-MUSCLES Treasury Survey: Measurements of the Ultraviolet Spectral Characteristics of Low-mass Exoplanetary Systems

NASA Astrophysics Data System (ADS)

Froning, Cynthia

2017-08-01

JWST will be able to observe the atmospheres of rocky planets transiting nearby M dwarfs. A few such planets are already known (around GJ1132, Proxima Cen, and Trappist-1) and TESS is predicted to find many more, including 14 habitable zone planets. To interpret observations of these exoplanets' atmospheres, we must understand the high-energy SED of their host stars: X-ray/EUV irradiation can erode a planet's gaseous envelope and FUV/NUV-driven photochemistry shapes an atmosphere's molecular abundances, including potential biomarkers like O2, O3, and CH4. Our MUSCLES Treasury Survey (Cycles 19+22) used Hubble/COS+STIS UV observations with contemporaneous X-ray and ground-based data to construct complete SEDs for 11 low-mass exoplanet hosts. MUSCLES is the most widely used database for early-M and K dwarf (>0.3 M_sun) irradiance spectra and has supported a wide range of atmospheric stability and biomarker modeling work. However, TESS will find most of its habitable planets transiting stars less massive than this, and these will be the planets to characterize with JWST. Here, we propose to expand the MUSCLES project to: (a) new M dwarf exoplanet hosts with varying properties; (b) reference M dwarfs below 0.3 solar masses that may be used as proxies for M dwarf planet hosts discovered after HST's lifetime; and (c) more rapidly rotating stars of GJ1132's mass to probe XUV evolution over gigayear timescales. We propose to gather the first panchromatic SEDs of rocky planet hosts GJ1132 and Trappist-1. This proposal extends proven methods to a key new sample of stars, upon which critically depends the long-term goal of studying habitable planet atmospheres with JWST and beyond.

Sex and parasites: genomic and transcriptomic analysis of Microbotryum lychnidis-dioicae, the biotrophic and plant-castrating anther smut fungus.

PubMed

Perlin, Michael H; Amselem, Joelle; Fontanillas, Eric; Toh, Su San; Chen, Zehua; Goldberg, Jonathan; Duplessis, Sebastien; Henrissat, Bernard; Young, Sarah; Zeng, Qiandong; Aguileta, Gabriela; Petit, Elsa; Badouin, Helene; Andrews, Jared; Razeeq, Dominique; Gabaldón, Toni; Quesneville, Hadi; Giraud, Tatiana; Hood, Michael E; Schultz, David J; Cuomo, Christina A

2015-06-16

The genus Microbotryum includes plant pathogenic fungi afflicting a wide variety of hosts with anther smut disease. Microbotryum lychnidis-dioicae infects Silene latifolia and replaces host pollen with fungal spores, exhibiting biotrophy and necrosis associated with altering plant development. We determined the haploid genome sequence for M. lychnidis-dioicae and analyzed whole transcriptome data from plant infections and other stages of the fungal lifecycle, revealing the inventory and expression level of genes that facilitate pathogenic growth. Compared to related fungi, an expanded number of major facilitator superfamily transporters and secretory lipases were detected; lipase gene expression was found to be altered by exposure to lipid compounds, which signaled a switch to dikaryotic, pathogenic growth. In addition, while enzymes to digest cellulose, xylan, xyloglucan, and highly substituted forms of pectin were absent, along with depletion of peroxidases and superoxide dismutases that protect the fungus from oxidative stress, the repertoire of glycosyltransferases and of enzymes that could manipulate host development has expanded. A total of 14% of the genome was categorized as repetitive sequences. Transposable elements have accumulated in mating-type chromosomal regions and were also associated across the genome with gene clusters of small secreted proteins, which may mediate host interactions. The unique absence of enzyme classes for plant cell wall degradation and maintenance of enzymes that break down components of pollen tubes and flowers provides a striking example of biotrophic host adaptation.

The effects of host-feeding on stability of discrete-time host-parasitoid population dynamic models.

PubMed

Emerick, Brooks; Singh, Abhyudai

2016-02-01

Discrete-time models are the traditional approach for capturing population dynamics of a host-parasitoid system. Recent work has introduced a semi-discrete framework for obtaining model update functions that connect host-parasitoid population levels from year-to-year. In particular, this framework uses differential equations to describe the host-parasitoid interaction during the time of year when they come in contact, allowing specific behaviors to be mechanistically incorporated. We use the semi-discrete approach to study the effects of host-feeding, which occurs when a parasitoid consumes a potential host larva without ovipositing. We find that host-feeding by itself cannot stabilize the system, and both populations exhibit behavior similar to the Nicholson-Bailey model. However, when combined with stabilizing mechanisms such as density-dependent host mortality, host-feeding contracts the region of parameter space that allows for a stable host-parasitoid equilibrium. In contrast, when combined with a density-dependent parasitoid attack rate, host-feeding expands the non-zero equilibrium stability region. Our results show that host-feeding causes inefficiency in the parasitoid population, which yields a higher population of hosts per generation. This suggests that host-feeding may have limited long-term impact in terms of suppressing host levels for biological control applications. Copyright © 2015 Elsevier Inc. All rights reserved.

Novel approach for identification of influenza virus host range and zoonotic transmissible sequences by determination of host-related associative positions in viral genome segments.

PubMed

Kargarfard, Fatemeh; Sami, Ashkan; Mohammadi-Dehcheshmeh, Manijeh; Ebrahimie, Esmaeil

2016-11-16

Recent (2013 and 2009) zoonotic transmission of avian or porcine influenza to humans highlights an increase in host range by evading species barriers. Gene reassortment or antigenic shift between viruses from two or more hosts can generate a new life-threatening virus when the new shuffled virus is no longer recognized by antibodies existing within human populations. There is no large scale study to help understand the underlying mechanisms of host transmission. Furthermore, there is no clear understanding of how different segments of the influenza genome contribute in the final determination of host range. To obtain insight into the rules underpinning host range determination, various supervised machine learning algorithms were employed to mine reassortment changes in different viral segments in a range of hosts. Our multi-host dataset contained whole segments of 674 influenza strains organized into three host categories: avian, human, and swine. Some of the sequences were assigned to multiple hosts. In point of fact, the datasets are a form of multi-labeled dataset and we utilized a multi-label learning method to identify discriminative sequence sites. Then algorithms such as CBA, Ripper, and decision tree were applied to extract informative and descriptive association rules for each viral protein segment. We found informative rules in all segments that are common within the same host class but varied between different hosts. For example, for infection of an avian host, HA14V and NS1230S were the most important discriminative and combinatorial positions. Host range identification is facilitated by high support combined rules in this study. Our major goal was to detect discriminative genomic positions that were able to identify multi host viruses, because such viruses are likely to cause pandemic or disastrous epidemics.

Sympatric diversification vs. immigration: deciphering host-plant specialization in a polyphagous insect, the stolbur phytoplasma vector Hyalesthes obsoletus (Cixiidae).

PubMed

Imo, Miriam; Maixner, Michael; Johannesen, Jes

2013-04-01

The epidemiology of vector transmitted plant diseases is highly influenced by dispersal and the host-plant range of the vector. Widening the vector's host range may increase transmission potential, whereas specialization may induce specific disease cycles. The process leading to a vector's host shift and its epidemiological outcome is therefore embedded in the frameworks of sympatric evolution vs. immigration of preadapted populations. In this study, we analyse whether a host shift of the stolbur phytoplasma vector, Hyalesthes obsoletus from field bindweed to stinging nettle in its northern distribution range evolved sympatrically or by immigration. The exploitation of stinging nettle has led to outbreaks of the grapevine disease bois noir caused by a stinging nettle-specific phytoplasma strain. Microsatellite data from populations from northern and ancestral ranges provide strong evidence for sympatric host-race evolution in the northern range: Host-plant associated populations were significantly differentiated among syntopic sites (0.054 < F(HT) < 0.098) and constant over 5 years. While gene flow was asymmetric from the old into the predicted new host race, which had significantly reduced genetic diversity, the genetic identity between syntopic host-race populations in the northern range was higher than between these populations and syntopic populations in ancestral ranges, where there was no evidence for genetic host races. Although immigration was detected in the northern field bindweed population, it cannot explain host-race diversification but suggests the introduction of a stinging nettle-specific phytoplasma strain by plant-unspecific vectors. The evolution of host races in the northern range has led to specific vector-based bois noir disease cycles. © 2013 Blackwell Publishing Ltd.

Novel microsatellite DNA markers indicate strict parthenogenesis and few genotypes in the invasive willow sawfly Nematus oligospilus.

PubMed

Caron, V; Norgate, M; Ede, F J; Nyman, T; Sunnucks, P

2013-02-01

Invasive organisms can have major impacts on the environment. Some invasive organisms are parthenogenetic in their invasive range and, therefore, exist as a number of asexual lineages (=clones). Determining the reproductive mode of invasive species has important implications for understanding the evolutionary genetics of such species, more especially, for management-relevant traits. The willow sawfly Nematus oligospilus Förster (Hymenoptera: Tenthredinidae) has been introduced unintentionally into several countries in the Southern Hemisphere where it has subsequently become invasive. To assess the population expansion, reproductive mode and host-plant relationships of this insect, microsatellite markers were developed and applied to natural populations sampled from the native and expanded range, along with sequencing of the cytochrome-oxidase I mitochondrial DNA (mtDNA) region. Other tenthredinids across a spectrum of taxonomic similarity to N. oligospilus and having a range of life strategies were also tested. Strict parthenogenesis was apparent within invasive N. oligospilus populations throughout the Southern Hemisphere, which comprised only a small number of genotypes. Sequences of mtDNA were identical for all individuals tested in the invasive range. The microsatellite markers were used successfully in several sawfly species, especially Nematus spp. and other genera of the Nematini tribe, with the degree of success inversely related to genetic divergence as estimated from COI sequences. The confirmation of parthenogenetic reproduction in N. oligospilus and the fact that it has a very limited pool of genotypes have important implications for understanding and managing this species and its biology, including in terms of phenotypic diversity, host relationships, implications for spread and future adaptive change. It would appear to be an excellent model study system for understanding evolution of invasive parthenogens that diverge without sexual reproduction and genetic recombination.

Host range, host specificity and hypothesized host shift events among viruses of lower vertebrates

PubMed Central

2011-01-01

The successful replication of a viral agent in a host is a complex process that often leads to a species specificity of the virus and can make interspecies transmission difficult. Despite this difficulty, natural host switch seems to have been frequent among viruses of lower vertebrates, especially fish viruses, since there are several viruses known to be able to infect a wide range of species. In the present review we will focus on well documented reports of broad host range, variations in host specificity, and host shift events hypothesized for viruses within the genera Ranavirus, Novirhabdovirus, Betanodavirus, Isavirus, and some herpesvirus. PMID:21592358

Cross-species infection trials reveal cryptic parasite varieties and a putative polymorphism shared among host species.

PubMed

Luijckx, Pepijn; Duneau, David; Andras, Jason P; Ebert, Dieter

2014-02-01

A parasite's host range can have important consequences for ecological and evolutionary processes but can be difficult to infer. Successful infection depends on the outcome of multiple steps and only some steps of the infection process may be critical in determining a parasites host range. To test this hypothesis, we investigated the host range of the bacterium Pasteuria ramosa, a Daphnia parasite, and determined the parasites success in different stages of the infection process. Multiple genotypes of Daphnia pulex, Daphnia longispina and Daphnia magna were tested with four Pasteuria genotypes using infection trials and an assay that determines the ability of the parasite to attach to the hosts esophagus. We find that attachment is not specific to host species but is specific to host genotype. This may suggest that alleles on the locus controlling attachment are shared among different host species that diverged 100 million year. However, in our trials, Pasteuria was never able to reproduce in nonnative host species, suggesting that Pasteuria infecting different host species are different varieties, each with a narrow host range. Our approach highlights the explanatory power of dissecting the steps of the infection process and resolves potentially conflicting reports on parasite host ranges. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Computational approaches for discovery of common immunomodulators in fungal infections: towards broad-spectrum immunotherapeutic interventions.

PubMed

Kidane, Yared H; Lawrence, Christopher; Murali, T M

2013-10-07

Fungi are the second most abundant type of human pathogens. Invasive fungal pathogens are leading causes of life-threatening infections in clinical settings. Toxicity to the host and drug-resistance are two major deleterious issues associated with existing antifungal agents. Increasing a host's tolerance and/or immunity to fungal pathogens has potential to alleviate these problems. A host's tolerance may be improved by modulating the immune system such that it responds more rapidly and robustly in all facets, ranging from the recognition of pathogens to their clearance from the host. An understanding of biological processes and genes that are perturbed during attempted fungal exposure, colonization, and/or invasion will help guide the identification of endogenous immunomodulators and/or small molecules that activate host-immune responses such as specialized adjuvants. In this study, we present computational techniques and approaches using publicly available transcriptional data sets, to predict immunomodulators that may act against multiple fungal pathogens. Our study analyzed data sets derived from host cells exposed to five fungal pathogens, namely, Alternaria alternata, Aspergillus fumigatus, Candida albicans, Pneumocystis jirovecii, and Stachybotrys chartarum. We observed statistically significant associations between host responses to A. fumigatus and C. albicans. Our analysis identified biological processes that were consistently perturbed by these two pathogens. These processes contained both immune response-inducing genes such as MALT1, SERPINE1, ICAM1, and IL8, and immune response-repressing genes such as DUSP8, DUSP6, and SPRED2. We hypothesize that these genes belong to a pool of common immunomodulators that can potentially be activated or suppressed (agonized or antagonized) in order to render the host more tolerant to infections caused by A. fumigatus and C. albicans. Our computational approaches and methodologies described here can now be applied to newly generated or expanded data sets for further elucidation of additional drug targets. Moreover, identified immunomodulators may be used to generate experimentally testable hypotheses that could help in the discovery of broad-spectrum immunotherapeutic interventions. All of our results are available at the following supplementary website: http://bioinformatics.cs.vt.edu/~murali/supplements/2013-kidane-bmc.

First reports of pseudorabies and winter ticks (Dermacentor albipictus) associated with an emerging feral swine (Sus scrofa) population in New Hampshire.

PubMed

Musante, Anthony R; Pedersen, Kerri; Hall, Parker

2014-01-01

The expansion of feral swine (Sus scrofa) populations into new geographic regions is of concern not only due to increased range but also because they carry diseases and parasites that pose a threat to humans, livestock, and wildlife into new areas. Recently, emerging feral swine populations have been reported in the northeastern US and due to their adaptive nature will likely continue to spread. During 2009-2012, 49 feral swine were removed from three counties in New Hampshire. Of these, serum samples were submitted from 34 for disease surveillance testing. One of the feral swine was antibody-positive for pseudorabies virus (PRV) making it the first documented infection in feral swine in New Hampshire. Infestations of winter tick (Dermacentor albipictus) were also documented on two of the feral swine which had only been reported previously on feral swine in Texas. Feral swine may not only serve as an important host for an economically important commercial swine pathogen like PRV, but they could also increase host diversity for parasites such as the winter tick, a species that can regionally impact moose (Alces alces) survival. These findings warrant further investigation of expanding and established feral swine populations in New Hampshire as pathogen hosts and support continued effort to reduce numbers or regionally eradicate feral swine.

Extending the Host Range of Bacteriophage Particles for DNA Transduction.

PubMed

Yosef, Ido; Goren, Moran G; Globus, Rea; Molshanski-Mor, Shahar; Qimron, Udi

2017-06-01

A major limitation in using bacteriophage-based applications is their narrow host range. Approaches for extending the host range have focused primarily on lytic phages in hosts supporting their propagation rather than approaches for extending the ability of DNA transduction into phage-restrictive hosts. To extend the host range of T7 phage for DNA transduction, we have designed hybrid particles displaying various phage tail/tail fiber proteins. These modular particles were programmed to package and transduce DNA into hosts that restrict T7 phage propagation. We have also developed an innovative generalizable platform that considerably enhances DNA transfer into new hosts by artificially selecting tails that efficiently transduce DNA. In addition, we have demonstrated that the hybrid particles transduce desired DNA into desired hosts. This study thus critically extends and improves the ability of the particles to transduce DNA into novel phage-restrictive hosts, providing a platform for myriad applications that require this ability. Copyright © 2017 Elsevier Inc. All rights reserved.

Evidence for a Common Toolbox Based on Necrotrophy in a Fungal Lineage Spanning Necrotrophs, Biotrophs, Endophytes, Host Generalists and Specialists

PubMed Central

Andrew, Marion; Barua, Reeta; Short, Steven M.; Kohn, Linda M.

2012-01-01

The Sclerotiniaceae (Ascomycotina, Leotiomycetes) is a relatively recently evolved lineage of necrotrophic host generalists, and necrotrophic or biotrophic host specialists, some latent or symptomless. We hypothesized that they inherited a basic toolbox of genes for plant symbiosis from their common ancestor. Maintenance and evolutionary diversification of symbiosis could require selection on toolbox genes or on timing and magnitude of gene expression. The genes studied were chosen because their products have been previously investigated as pathogenicity factors in the Sclerotiniaceae. They encode proteins associated with cell wall degradation: acid protease 1 (acp1), aspartyl protease (asps), and polygalacturonases (pg1, pg3, pg5, pg6), and the oxalic acid (OA) pathway: a zinc finger transcription factor (pac1), and oxaloacetate acetylhydrolase (oah), catalyst in OA production, essential for full symptom production in Sclerotinia sclerotiorum. Site-specific likelihood analyses provided evidence for purifying selection in all 8 pathogenicity-related genes. Consistent with an evolutionary arms race model, positive selection was detected in 5 of 8 genes. Only generalists produced large, proliferating disease lesions on excised Arabidopsis thaliana leaves and oxalic acid by 72 hours in vitro. In planta expression of oah was 10–300 times greater among the necrotrophic host generalists than necrotrophic and biotrophic host specialists; pac1 was not differentially expressed. Ability to amplify 6/8 pathogenicity related genes and produce oxalic acid in all genera are consistent with the common toolbox hypothesis for this gene sample. That our data did not distinguish biotrophs from necrotrophs is consistent with 1) a common toolbox based on necrotrophy and 2) the most conservative interpretation of the 3-locus housekeeping gene phylogeny – a baseline of necrotrophy from which forms of biotrophy emerged at least twice. Early oah overexpression likely expands the host range of necrotrophic generalists in the Sclerotiniaceae, while specialists and biotrophs deploy oah, or other as-yet-unknown toolbox genes, differently. PMID:22253834

A near death experience: Shigella manipulates host death machinery to silence innate immunity.

PubMed

Bronner, Denise N; O'Riordan, Mary Xd

2014-10-01

Release of mitochondrial contents often triggers inflammation and cell death, and modulating this process can be advantageous to invading pathogens. In this issue of The EMBO Journal, Andree and colleagues reveal new findings that an intracellular bacterial pathogen exploits apoptotic machinery to suppress host immune signaling, yet avoids cell death. This study emphasizes the need to expand our understanding of the roles played by pro‐apoptotic proteins in non‐death scenarios.

BioModels: expanding horizons to include more modelling approaches and formats

PubMed Central

Nguyen, Tung V N; Graesslin, Martin; Hälke, Robert; Ali, Raza; Schramm, Jochen; Wimalaratne, Sarala M; Kothamachu, Varun B; Rodriguez, Nicolas; Swat, Maciej J; Eils, Jurgen; Eils, Roland; Laibe, Camille; Chelliah, Vijayalakshmi

2018-01-01

Abstract BioModels serves as a central repository of mathematical models representing biological processes. It offers a platform to make mathematical models easily shareable across the systems modelling community, thereby supporting model reuse. To facilitate hosting a broader range of model formats derived from diverse modelling approaches and tools, a new infrastructure for BioModels has been developed that is available at http://www.ebi.ac.uk/biomodels. This new system allows submitting and sharing of a wide range of models with improved support for formats other than SBML. It also offers a version-control backed environment in which authors and curators can work collaboratively to curate models. This article summarises the features available in the current system and discusses the potential benefit they offer to the users over the previous system. In summary, the new portal broadens the scope of models accepted in BioModels and supports collaborative model curation which is crucial for model reproducibility and sharing. PMID:29106614

Lack of host specialization on winter annual grasses in the fungal seed bank pathogen Pyrenophora semeniperda

Treesearch

Julie Beckstead; Susan E. Meyer; Toby S. Ishizuka; Kelsey M. McEvoy; Craig E. Coleman

2016-01-01

Generalist plant pathogens may have wide host ranges, but many exhibit varying degrees of host specialization, with multiple pathogen races that have narrower host ranges. These races are often genetically distinct, with each race causing highest disease incidence on its host of origin. We examined host specialization in the seed pathogen Pyrenophora...

Reconstructing the gravitational field of the local Universe

NASA Astrophysics Data System (ADS)

Desmond, Harry; Ferreira, Pedro G.; Lavaux, Guilhem; Jasche, Jens

2018-03-01

Tests of gravity at the galaxy scale are in their infancy. As a first step to systematically uncovering the gravitational significance of galaxies, we map three fundamental gravitational variables - the Newtonian potential, acceleration and curvature - over the galaxy environments of the local Universe to a distance of approximately 200 Mpc. Our method combines the contributions from galaxies in an all-sky redshift survey, haloes from an N-body simulation hosting low-luminosity objects, and linear and quasi-linear modes of the density field. We use the ranges of these variables to determine the extent to which galaxies expand the scope of generic tests of gravity and are capable of constraining specific classes of model for which they have special significance. Finally, we investigate the improvements afforded by upcoming galaxy surveys.

Coccidian intestinal parasites in the Priapulidae (Priapulida).

PubMed

Saldarriaga, J F; Storch, V

1997-01-01

Four relatively uncommon members of the family Priapulidae (Priapulida) from very different parts of the world were examined to determine the presence of a parasitic coccidian in their midgut. The parasite was found in three of those priapulid species, Priapulopsis bicaudatus, P. australis, and Halicryptus higginsi, but not in the fourth one, Priapulus tuberculatospinosus. Using electron-microscopy techniques, we compared parasites of the different species with one another and with a parasite of Priapulus caudatus investigated by McLean in 1984. All of these parasites apparently belong to the same species and are likely to be Alveocystis intestinalis, a coccidian first described by Beltenev from P. caudatus and H. spinulosus. The present work greatly expands the geographical range of Alveocystis intestinalis and documents an uncommon case of low host specificity in eimeriid coccidians.

Evolutionary tools for phytosanitary risk analysis: phylogenetic signal as a predictor of host range of plant pests and pathogens

PubMed Central

Gilbert, Gregory S; Magarey, Roger; Suiter, Karl; Webb, Campbell O

2012-01-01

Assessing risk from a novel pest or pathogen requires knowing which local plant species are susceptible. Empirical data on the local host range of novel pests are usually lacking, but we know that some pests are more likely to attack closely related plant species than species separated by greater evolutionary distance. We use the Global Pest and Disease Database, an internal database maintained by the United States Department of Agriculture Animal and Plant Health Inspection Service – Plant Protection and Quarantine Division (USDA APHIS-PPQ), to evaluate the strength of the phylogenetic signal in host range for nine major groups of plant pests and pathogens. Eight of nine groups showed significant phylogenetic signal in host range. Additionally, pests and pathogens with more known hosts attacked a phylogenetically broader range of hosts. This suggests that easily obtained data – the number of known hosts and the phylogenetic distance between known hosts and other species of interest – can be used to predict which plant species are likely to be susceptible to a particular pest. This can facilitate rapid assessment of risk from novel pests and pathogens when empirical host range data are not yet available and guide efficient collection of empirical data for risk evaluation. PMID:23346231

Evolutionary tools for phytosanitary risk analysis: phylogenetic signal as a predictor of host range of plant pests and pathogens.

PubMed

Gilbert, Gregory S; Magarey, Roger; Suiter, Karl; Webb, Campbell O

2012-12-01

Assessing risk from a novel pest or pathogen requires knowing which local plant species are susceptible. Empirical data on the local host range of novel pests are usually lacking, but we know that some pests are more likely to attack closely related plant species than species separated by greater evolutionary distance. We use the Global Pest and Disease Database, an internal database maintained by the United States Department of Agriculture Animal and Plant Health Inspection Service - Plant Protection and Quarantine Division (USDA APHIS-PPQ), to evaluate the strength of the phylogenetic signal in host range for nine major groups of plant pests and pathogens. Eight of nine groups showed significant phylogenetic signal in host range. Additionally, pests and pathogens with more known hosts attacked a phylogenetically broader range of hosts. This suggests that easily obtained data - the number of known hosts and the phylogenetic distance between known hosts and other species of interest - can be used to predict which plant species are likely to be susceptible to a particular pest. This can facilitate rapid assessment of risk from novel pests and pathogens when empirical host range data are not yet available and guide efficient collection of empirical data for risk evaluation.

75 FR 66402 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-28

... necessary systems capacity to handle the additional traffic associated with the expanded range of strike... Effectiveness of Proposed Rule Change To Expand the Range of Strike Price Intervals for VIX Options October 21... amend Rule 24.9.01(e), Terms of Index Option Contracts, to expand the range of strike price intervals...

Innate immunity in rice

PubMed Central

Chen, Xuewei; Ronald, Pamela C.

2011-01-01

Advances in studies of rice innate immunity have led to the identification and characterization of host sensors encoding receptor kinases that perceive conserved microbial signatures. The non-RD domain, a newly recognized hallmark of these receptor kinases is highly expanded in rice (Oryza sativa) compared with Arabidopsis (Arabidopsis thaliana). Researchers have also identified a diverse array of microbial effectors from bacterial and fungal pathogens that triggers immune responses upon perception. These include both, effectors that indirectly target host Nucleotide binding site/Leucine rice repeat (NBS-LRR) proteins and transcription activator-like (TAL) effectors that directly bind promoters of host genes. Here we review the recognition and signaling events that govern rice innate immunity. PMID:21602092

A Brucella spp. Isolate from a Pac-Man Frog (Ceratophrys ornata) Reveals Characteristics Departing from Classical Brucellae

PubMed Central

Soler-Lloréns, Pedro F.; Quance, Chris R.; Lawhon, Sara D.; Stuber, Tod P.; Edwards, John F.; Ficht, Thomas A.; Robbe-Austerman, Suelee; O'Callaghan, David; Keriel, Anne

2016-01-01

Brucella are highly infectious bacterial pathogens responsible for brucellosis, a frequent worldwide zoonosis. The Brucella genus has recently expanded from 6 to 11 species, all of which were associated with mammals; The natural host range recently expanded to amphibians after some reports of atypical strains from frogs. Here we describe the first in depth phenotypic and genetic characterization of a Brucella strains isolated from a frog. Strain B13-0095 was isolated from a Pac-Man frog (Ceratophyrus ornate) at a veterinary hospital in Texas and was initially misidentified as Ochrobactrum anthropi. We found that B13-0095 belongs to a group of early-diverging brucellae that includes Brucella inopinata strain BO1 and the B. inopinata-like strain BO2, with traits that depart significantly from those of the “classical” Brucella spp. Analysis of B13-0095 genome sequence revealed several specific features that suggest that this isolate represents an intermediate between a soil associated ancestor and the host adapted “classical” species. Like strain BO2, B13-0095 does not possess the genes required to produce the perosamine based LPS found in classical Brucella, but has a set of genes that could encode a rhamnose based O-antigen. Despite this, B13-0095 has a very fast intracellular replication rate in both epithelial cells and macrophages. Finally, another major finding in this study is the bacterial motility observed for strains B13-0095, BO1, and BO2, which is remarkable for this bacterial genus. This study thus highlights several novel characteristics in strains belonging to an emerging group within the Brucella genus. Accurate identification tools for such atypical Brucella isolates and careful evaluation of their zoonotic potential, are urgently required. PMID:27734009

A Brucella spp. Isolate from a Pac-Man Frog (Ceratophrys ornata) Reveals Characteristics Departing from Classical Brucellae.

PubMed

Soler-Lloréns, Pedro F; Quance, Chris R; Lawhon, Sara D; Stuber, Tod P; Edwards, John F; Ficht, Thomas A; Robbe-Austerman, Suelee; O'Callaghan, David; Keriel, Anne

2016-01-01

Brucella are highly infectious bacterial pathogens responsible for brucellosis, a frequent worldwide zoonosis. The Brucella genus has recently expanded from 6 to 11 species, all of which were associated with mammals; The natural host range recently expanded to amphibians after some reports of atypical strains from frogs. Here we describe the first in depth phenotypic and genetic characterization of a Brucella strains isolated from a frog. Strain B13-0095 was isolated from a Pac-Man frog ( Ceratophyrus ornate ) at a veterinary hospital in Texas and was initially misidentified as Ochrobactrum anthropi . We found that B13-0095 belongs to a group of early-diverging brucellae that includes Brucella inopinata strain BO1 and the B. inopinata -like strain BO2, with traits that depart significantly from those of the "classical" Brucella spp. Analysis of B13-0095 genome sequence revealed several specific features that suggest that this isolate represents an intermediate between a soil associated ancestor and the host adapted "classical" species. Like strain BO2, B13-0095 does not possess the genes required to produce the perosamine based LPS found in classical Brucella , but has a set of genes that could encode a rhamnose based O-antigen. Despite this, B13-0095 has a very fast intracellular replication rate in both epithelial cells and macrophages. Finally, another major finding in this study is the bacterial motility observed for strains B13-0095, BO1, and BO2, which is remarkable for this bacterial genus. This study thus highlights several novel characteristics in strains belonging to an emerging group within the Brucella genus. Accurate identification tools for such atypical Brucella isolates and careful evaluation of their zoonotic potential, are urgently required.

The expanding host tree species spectrum of Cryptococcus gattii and Cryptococcus neoformans and their isolations from surrounding soil in India.

PubMed

Randhawa, H S; Kowshik, T; Chowdhary, Anuradha; Preeti Sinha, K; Khan, Z U; Sun, Sheng; Xu, Jianping

2008-12-01

This study reports the widespread prevalence of Cryptococcus neoformans and Cryptococcus gattii in decayed wood inside trunk hollows of 14 species representing 12 families of trees and from soil near the base of various host trees from Delhi and several places in the Indian states of Uttar Pradesh, Haryana, Tamil Nadu and Chandigarh Union Territory. Of the 311 trees from which samples were obtained, 64 (20.5%) were found to contain strains of the C. neoformans species complex. The number of trees positive for C. neoformans var grubii (serotypeA) was 51 (16.3%), for C. gattii (serotype B) 24 (7.7%) and for both C. neoformans and C. gattii 11 (3.5%). The overall prevalence of C. neoformans species complex in decayed wood samples was 19.9% (111/556). There was no obvious correlation between the prevalence of these two yeast species and the species of host trees. The data on prevalence of C. gattii (24%) and C. neoformans (26%) in soil around the base of some host trees indicated that soil is another important ecologic niche for these two Cryptococcus species in India. Among our sampled tree species, eight and six were recorded for the first time as hosts for C. neoformans var grubii and C. gattii, respectively. A longitudinal surveillance of 8 host tree species over 0.7 to 2.5 years indicated long term colonization of Polyalthia longifolia, Mimusops elengi and Manilkara hexandra trees by C. gattii and/or C. neoformans. The mating type was determined for 153 of the isolates, including 98 strains of serotype A and 55 of serotype B and all proved to be mating type alpha (MAT alpha). Our observations document the rapidly expanding spectrum of host tree species for C. gattii and C. neoformans and indicate that decayed woods of many tree species are potentially suitable ecological niches for both pathogens.

Search for Electromagnetic Counterparts to LIGO-Virgo Candidates: Expanded Very Large Array Observations

NASA Technical Reports Server (NTRS)

Lazio, Joseph; Keating, Katie; Jenet, F. A.; Kassim, N. E.

2011-01-01

This paper summarizes a search for radio wavelength counterparts to candidate gravitational wave events. The identification of an electromagnetic counterpart could provide a more complete understanding of a gravitational wave event, including such characteristics as the location and the nature of the progenitor. We used the Expanded Very Large Array (EVLA) to search six galaxies which were identified as potential hosts for two candidate gravitational wave events. We summarize our procedures and discuss preliminary results.

Mega-MUSCLES Treasury Survey: Measurements of the Ultraviolet Spectral Characteristics of Low-mass Exoplanetary Systems

NASA Astrophysics Data System (ADS)

Froning, Cynthia

2017-09-01

To interpret observations of exoplanets' atmospheres, we must understand the high-energy SEDs of their host stars. We propose to expand our Cycle 19/22 MUSCLES project to: (a) new M dwarf exoplanet hosts with varying properties; (b) reference M dwarfs below 0.3 solar masses that may be used as proxies for M dwarf planet hosts discovered after HST's lifetime; and (c) more rapidly rotating stars of GJ1132's mass to probe XUV evolution over gigayear timescales. We propose to gather the first panchromatic SEDs of rocky planet hosts GJ1132 and Trappist-1. This proposal extends proven methods to a key new sample of stars, upon which critically depends the long-term goal of studying habitable planet atmospheres with JWST and beyond.

Parasitic plants of the genus Cuscuta and their interaction with susceptible and resistant host plants

PubMed Central

Kaiser, Bettina; Vogg, Gerd; Fürst, Ursula B.; Albert, Markus

2015-01-01

By comparison with plant–microbe interaction, little is known about the interaction of parasitic plants with their hosts. Plants of the genus Cuscuta belong to the family of Cuscutaceae and comprise about 200 species, all of which live as stem holoparasites on other plants. Cuscuta spp. possess no roots nor fully expanded leaves and the vegetative portion appears to be a stem only. The parasite winds around plants and penetrates the host stems via haustoria, forming direct connections to the vascular bundles of their hosts to withdraw water, carbohydrates, and other solutes. Besides susceptible hosts, a few plants exist that exhibit an active resistance against infestation by Cuscuta spp. For example, cultivated tomato (Solanum lycopersicum) fends off Cuscuta reflexa by means of a hypersensitive-type response occurring in the early penetration phase. This report on the plant–plant dialog between Cuscuta spp. and its host plants focuses on the incompatible interaction of C. reflexa with tomato. PMID:25699071

Parasitic plants of the genus Cuscuta and their interaction with susceptible and resistant host plants.

PubMed

Kaiser, Bettina; Vogg, Gerd; Fürst, Ursula B; Albert, Markus

2015-01-01

By comparison with plant-microbe interaction, little is known about the interaction of parasitic plants with their hosts. Plants of the genus Cuscuta belong to the family of Cuscutaceae and comprise about 200 species, all of which live as stem holoparasites on other plants. Cuscuta spp. possess no roots nor fully expanded leaves and the vegetative portion appears to be a stem only. The parasite winds around plants and penetrates the host stems via haustoria, forming direct connections to the vascular bundles of their hosts to withdraw water, carbohydrates, and other solutes. Besides susceptible hosts, a few plants exist that exhibit an active resistance against infestation by Cuscuta spp. For example, cultivated tomato (Solanum lycopersicum) fends off Cuscuta reflexa by means of a hypersensitive-type response occurring in the early penetration phase. This report on the plant-plant dialog between Cuscuta spp. and its host plants focuses on the incompatible interaction of C. reflexa with tomato.

Wind for Schools: A National Data and Curricula Development Activity for Schools (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America?s Wind for Schools project addresses these issues by: 1) Developing Wind Application Centers (WACs) at universities; WAC students assist in implementing school wind turbines and participate in wind courses. 2) Installing small wind turbines at community 'host' schools. 3) Implementing teacher training with interactive curricula at each host school.

Wind for Schools: Fostering the Human Talent Supply Chain for a 20% Wind Energy Future (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.

2011-03-01

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America's Wind for Schools project addresses these issues by: 1) Developing Wind Application Centers (WACs) at universities; WAC students assist in implementing school wind turbines and participate in wind courses. 2) Installing small wind turbines at community "host" schools. 3) Implementing teacher training with interactive curricula at each host school.

Differential responses to guano fertilization among tropical tree species with varying functional traits.

PubMed

Young, Hillary S; McCauley, Douglas J; Dirzo, Rodolfo

2011-02-01

Seabirds often cause significant changes to soil properties, and seabird-dominated systems often host unique plant communities. This study experimentally (1) examined species-specific responses to seabird guano gradients, (2) considered the role that differential functional traits among species play in altering plant response to guano, and (3) investigated the implications of seabird guano on range-expanding species. Using a greenhouse fertilization experiment, we examined how guano fertilization affects the growth and functional traits of four tree species dominant in the Pacific Islands: Cocos nucifera, Pisonia grandis, Scaevola sericea, and Tournefortia argentea. In these systems, seabirds are frequently found in association with three of these four species; the remaining species, C. nucifera, is a recently proliferating species commonly found in the region but rarely associated with seabirds. We determined that responses to guano addition differed significantly between species in ways that were consistent with predictions based on differing functional traits among species. Notably, we demonstrated that C. nucifera showed no growth responses to guano additions, whereas all seabird-associated plants showed strong responses. These results provide experimental evidence of differential species response to guano additions, suggesting that differences in species functional traits may contribute to changes in plant communities in seabird-dominated areas, with seabird-associated species garnering performance advantages in these high-nutrient environments. Among these species, results also suggest that C. nucifera may have a competitive advantage in low-nutrient environments, providing an unusual example of how a range-expanding plant species can profit from low-nutrient environments.

Novel Methods to Determine Feeder Locational PV Hosting Capacity and PV Impact Signatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reno, Matthew J.; Coogan, Kyle; Seuss, John

Often PV hosting capacity analysis is performed for a limited number of distribution feeders. For medium - voltage distribution feeders, previous results generally analyze less than 20 feeders, and then the results are extrapolated out to similar types of feeders. Previous hosting capacity research has often focused on determining a single value for the hosting capacity for the entire feeder, whereas this research expands previous hosting capacity work to investigate all the regions of the feeder that may allow many different hosting capacity values wit h an idea called locational hosting capacity (LHC)to determine the largest PV size that canmore » be interconnected at different locations (buses) on the study feeders. This report discusses novel methods for analyzing PV interconnections with advanced simulati on methods. The focus is feeder and location - specific impacts of PV that determine the locational PV hosting capacity. Feeder PV impact signature are used to more precisely determine the local maximum hosting capacity of individual areas of the feeder. T he feeder signature provides improved interconnection screening with certain zones that show the risk of impact to the distribution feeder from PV interconnections.« less

Morphological variation in Echinorhynchus truttae Schrank, 1788 and the Echinorhynchus bothniensis Zdzitowiecki & Valtonen, 1987 species complex from freshwater fishes of northern Europe

PubMed Central

2013-01-01

Abstract Echinorhynchus truttae and the Echinorhynchus bothniensis species complex are common parasites of salmoniform and other fishes in northern Europe. Echinorhynchus bothniensis and its sibling species Echinorhynchus 'bothniensis' are thought to be closely related to the Nearctic Echinorhynchus leidyi Van Cleave, 1924 based on morphological similarity and common usage of a mysid intermediate host. This study provides the first analysis of morphological and meristic variation in Echinorhynchus truttae and expands our knowledge of anatomical variability in the Echinorhynchus bothniensis group. Morphological variability in Echinorhynchus truttae was found to be far greater than previously reported, with part of the variance attributable to sexual dimorphism. Echinorhynchus truttae, the two species of the Echinorhynchus bothniensis group and Echinorhynchus leidyi displayed considerable interspecific overlap in the ranges of all conventional morphological characters. However, Proboscis profiler, a tool for detecting acanthocephalan morphotypes using multivariate analysis of hook morphometrics, successfully separated Echinorhynchus truttae from the other taxa. The Echinorhynchus bothniensis species group could not be reliably distinguished from Echinorhynchus leidyi (or each other), providing further evidence of the affinity of these taxa. Observations on the distribution of Echinorhynchus truttae in its definitive host population are also reported. PMID:24723769

Platyhelminth Venom Allergen-Like (VAL) proteins: revealing structural diversity, class-specific features and biological associations across the phylum

PubMed Central

CHALMERS, IAIN W.; HOFFMANN, KARL F.

2012-01-01

SUMMARY During platyhelminth infection, a cocktail of proteins is released by the parasite to aid invasion, initiate feeding, facilitate adaptation and mediate modulation of the host immune response. Included amongst these proteins is the Venom Allergen-Like (VAL) family, part of the larger sperm coating protein/Tpx-1/Ag5/PR-1/Sc7 (SCP/TAPS) superfamily. To explore the significance of this protein family during Platyhelminthes development and host interactions, we systematically summarize all published proteomic, genomic and immunological investigations of the VAL protein family to date. By conducting new genomic and transcriptomic interrogations to identify over 200 VAL proteins (228) from species in all 4 traditional taxonomic classes (Trematoda, Cestoda, Monogenea and Turbellaria), we further expand our knowledge related to platyhelminth VAL diversity across the phylum. Subsequent phylogenetic and tertiary structural analyses reveal several class-specific VAL features, which likely indicate a range of roles mediated by this protein family. Our comprehensive analysis of platyhelminth VALs represents a unifying synopsis for understanding diversity within this protein family and a firm context in which to initiate future functional characterization of these enigmatic members. PMID:22717097

Echinococcus multilocularis in North America: the great unknown

PubMed Central

Massolo, Alessandro; Liccioli, Stefano; Budke, Christine; Klein, Claudia

2014-01-01

Over the last decade, studies have begun to shed light on the distribution and genetic characterization of Echinococcus multilocularis, the causative agent of alveolar echinococcosis (AE), in North America. Recent findings indicate that the parasite is likely expanding its range in the central region of the United States and Canada and that invasions of European strains might have occurred. In our review, we present the available data on E. multilocularis infections in wild and domestic animals and humans in North America and emphasize the lack of knowledge on the distribution of the parasite in wild and domestic hosts. Furthermore, we stress the need to better understand the complexity of host communities and their roles in shaping the transmission and distribution of the parasite. We hypothesize that a lack of knowledge about AE by North American physicians might result in the misdiagnosis of cases and an underestimation of disease incidence. The endemic presence of the parasite in urban areas and a recent human case in Alberta, Canada, suggest that the scientific community may need to reconsider the local public health risks, re-assess past cases that might have been overlooked and increase surveillance efforts to identify new cases of human AE. PMID:25531581

Molecular characterization and phylogenetic analysis of Fasciola hepatica from Peru.

PubMed

Ichikawa-Seki, Madoka; Ortiz, Pedro; Cabrera, Maria; Hobán, Cristian; Itagaki, Tadashi

2016-06-01

The causative agent of fasciolosis in South America is thought to be Fasciola hepatica. In this study, Fasciola flukes from Peru were analyzed to investigate their genetic structure and phylogenetic relationships with those from other countries. Fasciola flukes were collected from the three definitive host species: cattle, sheep, and pigs. They were identified as F. hepatica because mature sperms were observed in their seminal vesicles, and also they displayed Fh type, which has an identical fragment pattern to F. hepatica in the nuclear internal transcribed spacer 1. Eight haplotypes were obtained from the mitochondrial NADH dehydrogenase subunit 1 (nad1) sequences of Peruvian F. hepatica; however, no special difference in genetic structure was observed between the three host species. Its extremely low genetic diversity suggests that the Peruvian population was introduced from other regions. Nad1 haplotypes identical to those of Peruvian F. hepatica were detected in China, Uruguay, Italy, Iran, and Australia. Our results indicate that F. hepatica rapidly expanded its range due to human migration. Future studies are required to elucidate dispersal route of F. hepatica from Europe, its probable origin, to other areas, including Peru. Copyright © 2015. Published by Elsevier Ireland Ltd.

Parasites, ecosystems and sustainability: an ecological and complex systems perspective.

PubMed

Horwitz, Pierre; Wilcox, Bruce A

2005-06-01

Host-parasite relationships can be conceptualised either narrowly, where the parasite is metabolically dependent on the host, or more broadly, as suggested by an ecological-evolutionary and complex systems perspective. In this view Host-parasite relationships are part of a larger set of ecological and co-evolutionary interdependencies and a complex adaptive system. These interdependencies affect not just the hosts, vectors, parasites, the immediate agents, but also those indirectly or consequentially affected by the relationship. Host-parasite relationships also can be viewed as systems embedded within larger systems represented by ecological communities and ecosystems. So defined, it can be argued that Host-parasite relationships may often benefit their hosts and contribute significantly to the structuring of ecological communities. The broader, complex adaptive system view also contributes to understanding the phenomenon of disease emergence, the ecological and evolutionary mechanisms involved, and the role of parasitology in research and management of ecosystems in light of the apparently growing problem of emerging infectious diseases in wildlife and humans. An expanded set of principles for integrated parasite management is suggested by this perspective.

HIV-specific CD8+ T cells from HIV+ individuals receiving HAART can be expanded ex vivo to augment systemic and mucosal immunity in vivo.

PubMed

Chapuis, Aude G; Casper, Corey; Kuntz, Steve; Zhu, Jia; Tjernlund, Annelie; Diem, Kurt; Turtle, Cameron J; Cigal, Melinda L; Velez, Roxanne; Riddell, Stanley; Corey, Lawrence; Greenberg, Philip D

2011-05-19

Most HIV+ individuals require lifelong highly active antiretroviral therapy (HAART) to suppress HIV replication, but fail to eliminate the virus in part because of residual replication in gut-associated lymphoid tissues (GALT). Naturally elicited HIV-specific CD8+ T cells generated in the acute and chronic infectious phases exhibit antiviral activity, but decrease in number after HAART. Therapeutic vaccines represent a potential strategy to expand cellular responses, although previous efforts have been largely unsuccessful, conceivably because of a lack of responding HIV-specific central-memory CD8+ T cells (Tcm). To determine whether patients receiving HAART possess CD8+ T cells with Tcm qualities that are amenable to augmentation, HIV-specific CD8+ T-cell clones were derived from HIV-reactive CD28+CD8+ T-cell lines isolated from 7 HIV+ HAART-treated patients, expanded ex vivo, and reinfused into their autologous host. Tracking of the cells in vivo revealed that clones could persist for ≥ 84 days, maintain expression and/or re-express CD28, up-regulate CD62L, secrete IL-2, proliferate on cognate Ag encounter and localize to the rectal mucosa. These results suggest some infused cells exhibited phenotypic and functional characteristics shared with Tcm in vivo, and imply that more effective therapeutic vaccination strategies targeting CD8+ Tcm in patients on HAART might provide hosts with expanded, long-lasting immune responses not only systemically but also in GALT.

Surveying N2O-producing pathways in bacteria.

PubMed

Stein, Lisa Y

2011-01-01

Nitrous oxide (N(2)O) is produced by bacteria as an intermediate of both dissimilatory and detoxification pathways under a range of oxygen levels, although the majority of N(2)O is released in suboxic to anoxic environments. N(2)O production under physiologically relevant conditions appears to require the reduction of nitric oxide (NO) produced from the oxidation of hydroxylamine (nitrification), reduction of nitrite (denitrification), or by host cells of pathogenic bacteria. In a single bacterial isolate, N(2)O-producing pathways can be complex, overlapping, involve multiple enzymes with the same function, and require multiple layers of regulatory machinery. This overview discusses how to identify known N(2)O-producing inventory and regulatory sequences within bacterial genome sequences and basic physiological approaches for investigating the function of that inventory. A multitude of review articles have been published on individual enzymes, pathways, regulation, and environmental significance of N(2)O-production encompassing a large diversity of bacterial isolates. The combination of next-generation deep sequencing platforms, emerging proteomics technologies, and basic microbial physiology can be used to expand what is known about N(2)O-producing pathways in individual bacterial species to discover novel inventory and unifying features of pathways. A combination of approaches is required to understand and generalize the function and control of N(2)O production across a range of temporal and spatial scales within natural and host environments. Copyright © 2011 Elsevier Inc. All rights reserved.

2.1 Natural History of Highly Pathogenic Avian Influenza H5N1

PubMed Central

Sonnberg, Stephanie; Webby, Richard J.; Webster, Robert G.

2013-01-01

The ecology of highly pathogenic avian influenza (HPAI) H5N1 has significantly changed from sporadic outbreaks in terrestrial poultry to persistent circulation in terrestrial and aquatic poultry and potentially in wild waterfowl. A novel genotype of HPAI H5N1 arose in 1996 in southern China and through ongoing mutation, reassortment, and natural selection, has diverged into distinct lineages and expanded into multiple reservoir hosts. The evolution of Goose/Guangdong-lineage highly pathogenic H5N1 viruses is ongoing: while stable interactions exist with some reservoir hosts, these viruses are continuing to evolve and adapt to others, and pose an un-calculable risk to sporadic hosts, including humans. PMID:23735535

Wind for Schools: Developing Educational Programs to Train the Next Generation of Wind Energy Experts (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.; Flowers, L.; Kelly, M.

2009-05-01

As the world moves toward a vision of expanded wind energy, the industry is faced with the challenges of obtaining a skilled workforce and addressing local wind development concerns. Wind Powering America's Wind for Schools Program works to address these issues. The program installs small wind turbines at community "host" schools while developing wind application centers at higher education institutions. Teacher training with interactive and interschool curricula is implemented at each host school, while students at the universities assist in implementing the host school systems while participating in other wind course work. This poster provides an overview of the program'smore » objectives, goals, approach, and results.« less

Evolution, multiple acquisition, and localization of endosymbionts in bat flies (Diptera: Hippoboscoidea: Streblidae and Nycteribiidae).

PubMed

Morse, Solon F; Bush, Sarah E; Patterson, Bruce D; Dick, Carl W; Gruwell, Matthew E; Dittmar, Katharina

2013-05-01

Bat flies are a diverse clade of obligate ectoparasites on bats. Like most blood-feeding insects, they harbor endosymbiotic prokaryotes, but the origins and nature of these symbioses are still poorly understood. To expand the knowledge of bacterial associates in bat flies, the diversity and evolution of the dominant endosymbionts in six of eight nominal subfamilies of bat flies (Streblidae and Nycteribiidae) were studied. Furthermore, the localization of endosymbionts and their transmission across developmental stages within the family Streblidae were explored. The results show diverse microbial associates in bat flies, with at least four ancestral invasions of distantly related microbial lineages throughout bat fly evolution. Phylogenetic relationships support the presence of at least two novel symbiont lineages (here clades B and D), and extend the geographic and taxonomic range of a previously documented lineage ("Candidatus Aschnera chinzeii"; here clade A). Although these lineages show reciprocally monophyletic clusters with several bat fly host clades, their phylogenetic relationships generally do not reflect current bat fly taxonomy or phylogeny. However, within some endosymbiont clades, congruent patterns of symbiont-host divergence are apparent. Other sequences identified in this study fall into the widely distributed, highly invasive, insect-associated Arsenophonus lineage and may be the result of symbiont replacements and/or transient infections (here clade C). Vertical transmission of endosymbionts of clades B and D is supported by fluorescent signal (fluorescent in situ hybridization [FISH]) and microbial DNA detection across developmental stages. The fluorescent bacterial signal is consistently localized within structures resembling bacteriomes, although their anatomical position differs by host fly clade. In summary, the results suggest an obligate host-endosymbiont relationship for three of the four known symbiont clades associated with bat flies (clades A, B, and D).

Evolution, Multiple Acquisition, and Localization of Endosymbionts in Bat Flies (Diptera: Hippoboscoidea: Streblidae and Nycteribiidae)

PubMed Central

Morse, Solon F.; Bush, Sarah E.; Patterson, Bruce D.; Dick, Carl W.; Gruwell, Matthew E.

2013-01-01

Bat flies are a diverse clade of obligate ectoparasites on bats. Like most blood-feeding insects, they harbor endosymbiotic prokaryotes, but the origins and nature of these symbioses are still poorly understood. To expand the knowledge of bacterial associates in bat flies, the diversity and evolution of the dominant endosymbionts in six of eight nominal subfamilies of bat flies (Streblidae and Nycteribiidae) were studied. Furthermore, the localization of endosymbionts and their transmission across developmental stages within the family Streblidae were explored. The results show diverse microbial associates in bat flies, with at least four ancestral invasions of distantly related microbial lineages throughout bat fly evolution. Phylogenetic relationships support the presence of at least two novel symbiont lineages (here clades B and D), and extend the geographic and taxonomic range of a previously documented lineage (“Candidatus Aschnera chinzeii”; here clade A). Although these lineages show reciprocally monophyletic clusters with several bat fly host clades, their phylogenetic relationships generally do not reflect current bat fly taxonomy or phylogeny. However, within some endosymbiont clades, congruent patterns of symbiont-host divergence are apparent. Other sequences identified in this study fall into the widely distributed, highly invasive, insect-associated Arsenophonus lineage and may be the result of symbiont replacements and/or transient infections (here clade C). Vertical transmission of endosymbionts of clades B and D is supported by fluorescent signal (fluorescent in situ hybridization [FISH]) and microbial DNA detection across developmental stages. The fluorescent bacterial signal is consistently localized within structures resembling bacteriomes, although their anatomical position differs by host fly clade. In summary, the results suggest an obligate host-endosymbiont relationship for three of the four known symbiont clades associated with bat flies (clades A, B, and D). PMID:23435889

Ecological disequilibrium drives insect pest and pathogen accumulation in non-native trees

PubMed Central

Burgess, Treena I.; Le Roux, Johannes J.; Richardson, David M.; Slippers, Bernard; Wingfield, Michael J.

2017-01-01

Abstract Non-native trees have become dominant components of many landscapes, including urban ecosystems, commercial forestry plantations, fruit orchards and as invasives in natural ecosystems. Often, these trees have been separated from their natural enemies (i.e. insects and pathogens) leading to ecological disequilibrium, that is, the immediate breakdown of historically co-evolved interactions once introduced into novel environments. Long-established, non-native tree plantations provide useful experiments to explore the dimensions of such ecological disequilibria. We quantify the status quo of non-native insect pests and pathogens catching up with their tree hosts (planted Acacia, Eucalyptus and Pinus species) in South Africa, and examine which native South African enemy species utilize these trees as hosts. Interestingly, pines, with no confamilial relatives in South Africa and the longest residence time (almost two centuries), have acquired only one highly polyphagous native pathogen. This is in contrast to acacias and eucalypts, both with many native and confamilial relatives in South Africa that have acquired more native pathogens. These patterns support the known role of phylogenetic relatedness of non-native and native floras in influencing the likelihood of pathogen shifts between them. This relationship, however, does not seem to hold for native insects. Native insects appear far more likely to expand their feeding habits onto non-native tree hosts than are native pathogens, although they are generally less damaging. The ecological disequilibrium conditions of non-native trees are deeply rooted in the eco-evolutionary experience of the host plant, co-evolved natural enemies and native organisms from the introduced range. We should expect considerable spatial and temporal variation in ecological disequilibrium conditions among non-native taxa, which can be significantly influenced by biosecurity and management practices. PMID:28013250

Expansion of natural killer cell receptor (CD94/NKG2A)-expressing cytolytic CD8 T cells and CD4+CD25+ regulatory T cells from the same cord blood unit.

PubMed

Tanaka, Junji; Sugita, Junichi; Kato, Naoko; Toubai, Tomomi; Ibata, Makoto; Shono, Yusuke; Ota, Shuichi; Kondo, Takeshi; Kobayashi, Takahiko; Kobayashi, Masanobu; Asaka, Masahiro; Imamura, Masahiro

2007-10-01

Cord blood contains a significant number of precursor cells that differentiate to cytotoxic effector cells and immunoregulatory cells. We tried to expand inhibitory natural killer cell receptor CD94-expressing CD8 T cells with cytolytic activity and CD4(+)CD25(+) regulatory T cells from the same cord cell unit. Cytotoxic CD94-expressing CD8 T cells were expanded from CD4-depleted cord blood using an immobilized anti-CD3 monoclonal antibody and a cytokine and also CD4(+)CD25(+) regulatory T cells were expanded from a CD4-enriched fraction derived from the same cord blood unit using anti-CD3/CD28 monoclonal antibody-coated Dynabeads and cytokines. We were able to obtain a more than 1000-fold expansion of CD94-expressing CD8 T cells and a more than 50-fold expansion of CD4(+)CD25(+) cells from the same cord blood unit. These expanded CD4(+)CD25(+) cells expressed FoxP3 mRNA at a level about 100-fold higher than that in isolated CD25(-) cells and could suppress allogeneic mixed lymphocyte culture by >80% (effector cells: CD4(+)CD25(+) cells = 2:1). Cytolytic activities of purified CD94-expressing cells detected by a 4-hour (51)Cr release assay against K562 were >60%. Coculture of CD94-expressing cells with expanded CD4(+)CD25(+) cells did not have any effect on cytolytic activities of purified CD94-expressing cells against K562 cells. These expanded cytolytic CD94-expressing CD8 cells might be able to induce a graft-vs-leukemia effect without enhancing graft-vs-host disease, and CD4(+)CD25(+) cells might be able to suppress allogeneic responses, including graft-vs-host disease and graft rejection after cord blood transplantation.

Projecting the Global Distribution of the Emerging Amphibian Fungal Pathogen, Batrachochytrium dendrobatidis, Based on IPCC Climate Futures.

PubMed

Xie, Gisselle Yang; Olson, Deanna H; Blaustein, Andrew R

2016-01-01

Projected changes in climate conditions are emerging as significant risk factors to numerous species, affecting habitat conditions and community interactions. Projections suggest species range shifts in response to climate change modifying environmental suitability and is supported by observational evidence. Both pathogens and their hosts can shift ranges with climate change. We consider how climate change may influence the distribution of the emerging infectious amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), a pathogen associated with worldwide amphibian population losses. Using an expanded global Bd database and a novel modeling approach, we examined a broad set of climate metrics to model the Bd-climate niche globally and regionally, then project how climate change may influence Bd distributions. Previous research showed that Bd distribution is dependent on climatic variables, in particular temperature. We trained a machine-learning model (random forest) with the most comprehensive global compilation of Bd sampling records (~5,000 site-level records, mid-2014 summary), including 13 climatic variables. We projected future Bd environmental suitability under IPCC scenarios. The learning model was trained with combined worldwide data (non-region specific) and also separately per region (region-specific). One goal of our study was to estimate of how Bd spatial risks may change under climate change based on the best available data. Our models supported differences in Bd-climate relationships among geographic regions. We projected that Bd ranges will shift into higher latitudes and altitudes due to increased environmental suitability in those regions under predicted climate change. Specifically, our model showed a broad expansion of areas environmentally suitable for establishment of Bd on amphibian hosts in the temperate zones of the Northern Hemisphere. Our projections are useful for the development of monitoring designs in these areas, especially for sensitive species and those vulnerable to multiple threats.

Bats, Trypanosomes, and Triatomines in Ecuador: New Insights into the Diversity, Transmission, and Origins of Trypanosoma cruzi and Chagas Disease.

PubMed

Pinto, C Miguel; Ocaña-Mayorga, Sofía; Tapia, Elicio E; Lobos, Simón E; Zurita, Alejandra P; Aguirre-Villacís, Fernanda; MacDonald, Amber; Villacís, Anita G; Lima, Luciana; Teixeira, Marta M G; Grijalva, Mario J; Perkins, Susan L

2015-01-01

The generalist parasite Trypanosoma cruzi has two phylogenetic lineages associated almost exclusively with bats-Trypanosoma cruzi Tcbat and the subspecies T. c. marinkellei. We present new information on the genetic variation, geographic distribution, host associations, and potential vectors of these lineages. We conducted field surveys of bats and triatomines in southern Ecuador, a country endemic for Chagas disease, and screened for trypanosomes by microscopy and PCR. We identified parasites at species and genotype levels through phylogenetic approaches based on 18S ribosomal RNA (18S rRNA) and cytochrome b (cytb) genes and conducted a comparison of nucleotide diversity of the cytb gene. We document for the first time T. cruzi Tcbat and T. c. marinkellei in Ecuador, expanding their distribution in South America to the western side of the Andes. In addition, we found the triatomines Cavernicola pilosa and Triatoma dispar sharing shelters with bats. The comparisons of nucleotide diversity revealed a higher diversity for T. c. marinkellei than any of the T. c. cruzi genotypes associated with Chagas disease. Findings from this study increased both the number of host species and known geographical ranges of both parasites and suggest potential vectors for these two trypanosomes associated with bats in rural areas of southern Ecuador. The higher nucleotide diversity of T. c. marinkellei supports a long evolutionary relationship between T. cruzi and bats, implying that bats are the original hosts of this important parasite.

Worldwide phylogenetic relationship of avian poxviruses

USGS Publications Warehouse

Gyuranecz, Miklós; Foster, Jeffrey T.; Dán, Ádám; Ip, Hon S.; Egstad, Kristina F.; Parker, Patricia G.; Higashiguchi, Jenni M.; Skinner, Michael A.; Höfle, Ursula; Kreizinger, Zsuzsa; Dorrestein, Gerry M.; Solt, Szabolcs; Sós, Endre; Kim, Young Jun; Uhart, Marcela; Pereda, Ariel; González-Hein, Gisela; Hidalgo, Hector; Blanco, Juan-Manuel; Erdélyi, Károly

2013-01-01

Poxvirus infections have been found in 230 species of wild and domestic birds worldwide in both terrestrial and marine environments. This ubiquity raises the question of how infection has been transmitted and globally dispersed. We present a comprehensive global phylogeny of 111 novel poxvirus isolates in addition to all available sequences from GenBank. Phylogenetic analysis of Avipoxvirus genus has traditionally relied on one gene region (4b core protein). In this study we have expanded the analyses to include a second locus (DNA polymerase gene), allowing for a more robust phylogenetic framework, finer genetic resolution within specific groups and the detection of potential recombination. Our phylogenetic results reveal several major features of avipoxvirus evolution and ecology and propose an updated avipoxvirus taxonomy, including three novel subclades. The characterization of poxviruses from 57 species of birds in this study extends the current knowledge of their host range and provides the first evidence of the phylogenetic effect of genetic recombination of avipoxviruses. The repeated occurrence of avian family or order-specific grouping within certain clades (e.g. starling poxvirus, falcon poxvirus, raptor poxvirus, etc.) indicates a marked role of host adaptation, while the sharing of poxvirus species within prey-predator systems emphasizes the capacity for cross-species infection and limited host adaptation. Our study provides a broad and comprehensive phylogenetic analysis of the Avipoxvirus genus, an ecologically and environmentally important viral group, to formulate a genome sequencing strategy that will clarify avipoxvirus taxonomy.

Probing the end of reionization with the near zones of z ≳ 6 QSOs

NASA Astrophysics Data System (ADS)

Keating, Laura C.; Haehnelt, Martin G.; Cantalupo, Sebastiano; Puchwein, Ewald

2015-11-01

QSO near zones are an important probe of the ionization state of the intergalactic medium (IGM) at z ˜ 6-7, at the end of reionization. We present here high-resolution cosmological 3D radiative transfer simulations of QSO environments for a wide range of host halo masses, 1010-12.5 M⊙. Our simulated near zones reproduce both the overall decrease of observed near-zone sizes at 6 < z < 7 and their scatter. The observable near-zone properties in our simulations depend only very weakly on the mass of the host halo. The size of the H II region expanding into the IGM is generally limited by (super-)Lyman Limit systems loosely associated with (low-mass) dark matter haloes. This leads to a strong dependence of near-zone size on direction and drives the large observed scatter. In the simulation centred on our most massive host halo, many sightlines show strong red damping wings even for initial volume averaged neutral hydrogen fractions as low as ˜10-3. For QSO lifetimes long enough to allow growth of the central supermassive black hole while optically bright, we can reproduce the observed near zone of ULAS J1120+0641 only with an IGM that is initially neutral. Our results suggest that larger samples of z > 7 QSOs will provide important constraints on the evolution of the neutral hydrogen fraction and thus on how late reionization ends.

Bats, Trypanosomes, and Triatomines in Ecuador: New Insights into the Diversity, Transmission, and Origins of Trypanosoma cruzi and Chagas Disease

PubMed Central

Pinto, C. Miguel; Ocaña-Mayorga, Sofía; Tapia, Elicio E.; Lobos, Simón E.; Zurita, Alejandra P.; Aguirre-Villacís, Fernanda; MacDonald, Amber; Villacís, Anita G.; Lima, Luciana; Teixeira, Marta M. G.; Grijalva, Mario J.; Perkins, Susan L.

2015-01-01

The generalist parasite Trypanosoma cruzi has two phylogenetic lineages associated almost exclusively with bats—Trypanosoma cruzi Tcbat and the subspecies T. c. marinkellei. We present new information on the genetic variation, geographic distribution, host associations, and potential vectors of these lineages. We conducted field surveys of bats and triatomines in southern Ecuador, a country endemic for Chagas disease, and screened for trypanosomes by microscopy and PCR. We identified parasites at species and genotype levels through phylogenetic approaches based on 18S ribosomal RNA (18S rRNA) and cytochrome b (cytb) genes and conducted a comparison of nucleotide diversity of the cytb gene. We document for the first time T. cruzi Tcbat and T. c. marinkellei in Ecuador, expanding their distribution in South America to the western side of the Andes. In addition, we found the triatomines Cavernicola pilosa and Triatoma dispar sharing shelters with bats. The comparisons of nucleotide diversity revealed a higher diversity for T. c. marinkellei than any of the T. c. cruzi genotypes associated with Chagas disease. Findings from this study increased both the number of host species and known geographical ranges of both parasites and suggest potential vectors for these two trypanosomes associated with bats in rural areas of southern Ecuador. The higher nucleotide diversity of T. c. marinkellei supports a long evolutionary relationship between T. cruzi and bats, implying that bats are the original hosts of this important parasite. PMID:26465748

Worldwide Phylogenetic Relationship of Avian Poxviruses

PubMed Central

Foster, Jeffrey T.; Dán, Ádám; Ip, Hon S.; Egstad, Kristina F.; Parker, Patricia G.; Higashiguchi, Jenni M.; Skinner, Michael A.; Höfle, Ursula; Kreizinger, Zsuzsa; Dorrestein, Gerry M.; Solt, Szabolcs; Sós, Endre; Kim, Young Jun; Uhart, Marcela; Pereda, Ariel; González-Hein, Gisela; Hidalgo, Hector; Blanco, Juan-Manuel; Erdélyi, Károly

2013-01-01

Poxvirus infections have been found in 230 species of wild and domestic birds worldwide in both terrestrial and marine environments. This ubiquity raises the question of how infection has been transmitted and globally dispersed. We present a comprehensive global phylogeny of 111 novel poxvirus isolates in addition to all available sequences from GenBank. Phylogenetic analysis of the Avipoxvirus genus has traditionally relied on one gene region (4b core protein). In this study we expanded the analyses to include a second locus (DNA polymerase gene), allowing for a more robust phylogenetic framework, finer genetic resolution within specific groups, and the detection of potential recombination. Our phylogenetic results reveal several major features of avipoxvirus evolution and ecology and propose an updated avipoxvirus taxonomy, including three novel subclades. The characterization of poxviruses from 57 species of birds in this study extends the current knowledge of their host range and provides the first evidence of the phylogenetic effect of genetic recombination of avipoxviruses. The repeated occurrence of avian family or order-specific grouping within certain clades (e.g., starling poxvirus, falcon poxvirus, raptor poxvirus, etc.) indicates a marked role of host adaptation, while the sharing of poxvirus species within prey-predator systems emphasizes the capacity for cross-species infection and limited host adaptation. Our study provides a broad and comprehensive phylogenetic analysis of the Avipoxvirus genus, an ecologically and environmentally important viral group, to formulate a genome sequencing strategy that will clarify avipoxvirus taxonomy. PMID:23408635

A baseline analysis of the distribution, host-range, and severity of the rust Puccinia Psidii in the Hawaiian islands, 2005-2010

USGS Publications Warehouse

Anderson, Robert C.

2012-01-01

Puccinia psidii was first described by Winter (1884) on guava (Psidium guajava L.) in Brazil. The rust is still a major pest of native guava in Brazil and is often referred to as “guava rust” internationally. It is unusual among rust fungi because of its broad and ever-expanding host-range within the Myrtaceae plant family (Simpson et al. 2006). The pathogen is regarded as a major threat to Eucalyptus plantations and other Myrtaceae worldwide (Coutinho et al. 1998, Grgurinovic et al. 2006, Glen et al. 2007). Infections of leaves and meristems are particularly severe on susceptible seedlings, cuttings, young trees, and coppice, causing plants to be stunted and multi-branched, inhibiting normal growth and development, and sometimes causing death to young seedlings (Booth et al. 2000, Rayachhetry et al. 2001). The fungus has expanded its host-range in Brazil, affecting both native and introduced Myrtaceae (Coutinho et al. 1998).

Since its discovery in 1884, P. psidii has continually been discovered to have an expanding host-range within the Myrtaceae, affecting hosts throughout much of South and Central America and the Caribbean. Spreading out originally from Brazil in 1884, the fungus has been reported on hosts in the following countries (first record in parentheses): Paraguay (1884), Uruguay (1889), Ecuador (1891), Colombia (1913), Puerto Rico (1913), Cuba (1926), Dominican Republic (1933), Venezuela (1934), Jamaica (1936), Argentina (1946), Dominica (1948), Trinidad and Tobago (1951), Guatemala (1968), United States (Florida; 1977), Mexico (1981), El Salvador (1987), and Costa Rica (1998) (Simpson et al. 2006). It is possible that P. psidii was present in El Salvador and Costa Rica prior to 1980, but was not reported until 1987 and 1998, respectively.

Until recently, Puccinia psidii was restricted to the Neotropics, Mexico, and the state of Florida in the United States. While the rust has been present in Florida for over 30 years, only recently has it spread westward. Although possibly present earlier, P. psidii was found in California in November 2005 in a nursery in San Diego County on Myrtus communis and documented by a report in a nursery newsletter (Mellano 2006). Puccinia psidii was first found in Hawai`i on a young plant of `ōhi`a (Metrosideros polymorpha) in April 2005, in a nursery on the island of O`ahu (Killgore and Heu 2005; Uchida et al. 2006). The fungus subsequently spread to most islands of the Hawaiian chain, infecting `ōhi`a and other myrtaceous hosts (Hauff 2006, Anderson et al. 2007). P. psidii was first found in Japan in May 2007 on cultivated `ōhi`a (Kawanishi et al. 2009).

Most recently, a rust identified as Uredo rangelii was discovered in April 2010 in New South Wales, Australia (Carnegie et al. 2010). This rust is closely related to Puccinia psidii and is part of the guava rust complex described by Simpson et al. (2006). Although treated as a separate species by Simpson et al. (2006), many authors now consider U. rangelii a synonym for U. psidii, which is the anamorph (asexual stage) of P. psidii, and therefore, the same species (Glen et al. 2007, Carnegie et al. 2010). Because of the large diversity of native Myrtaceae present in Australia, the number of Myrtaceae hosts attacked by species of the guava rust complex will likely grow now that U. rangelii has arrived and is spreading in the country. As of this writing (June 2011), 94 species of Myrtaceae have been identified as hosts of U. rangelii in the states of New South Wales and Queensland. Damage is severe on nearly one-third of the species affected, and 16 of these species are threatened or endangered native species (Secretary of Australia, May 2011).

The presence of Puccinia psidii in Hawai`i is particularly alarming for at least two reasons: (1) M. polymorpha is the dominant overstory tree of the native forest, and (2) P. psidii is now established in the Pacific region, where numerous Myrtaceae species are native. Native ecosystems in Hawai`i and the Pacific could be seriously affected by the spread of P. psidii, as both native and introduced Myrtaceae are significant components of many different plant communities throughout the region (Glen et al. 2007). Because the guava rust complex (i.e., P. psidii and U. rangelii) now attacks well over 100 species of Myrtaceae worldwide, it is currently a priority for international quarantine and import restrictions in an effort to prevent further spread among Australasian and Pacific Myrtaceae.

Several different studies have been done to determine what degree of genetic variation exists between isolates of Puccinia psidii from many different host plants and many different locations (Langrell et al. 2008, Kawanishi et al. 2009, Kadooka 2010, Graça et al. 2011). So far, all of these studies have shown that all of the Hawaiian samples tested so far have had the same genetic composition. Given that the P. psidii strain in Hawai`i has continually been shown for over five years to lack genetic variation at microsatellite marker sites (which are believed to undergo relatively rapid genetic change), a baseline evaluation of incidence and severity should be especially valuable to provide comparisons with future conditions.

Worldwide, 23 Neotropical species in 11 genera and 59 Australasian and Pacific species in 13 genera had been recorded as hosts of Puccinia psidii before 2010 (Simpson et al. 2006, Anderson et al. 2007). Of those 82 species known to be hosts elsewhere, 42 are cultivated or naturalized in Hawai`i. Because of its wide host-range and aggressive pathogenicity, rust disease caused by P. psidii poses a considerable disease threat to many native and cultivated Myrtaceae throughout the world (Coutinho et al. 1998, Booth et al. 2000, Simpson et al. 2006). However, there are few reports comparing the severity of rust infection on native, introduced, and cultivated Myrtaceae (Rayachhetry et al. 2001, Perez et al. 2010). Since government agencies and the public are concerned about the extent of the rust movement within and to Hawai`i (Loope and La Rosa 2008, Loope 2010), there is a need to better understand the incidence, severity, and distribution of P. psidii in Hawai`i. To address that need, this research project was initiated to survey forests, surrounding plant communities, botanical gardens, and commercial nurseries to detect the presence and severity of P. psidii rust infections throughout Hawai`i on plants in the Myrtaceae family. This study provides a baseline on the host distribution and severity to compare current and future impacts of rust infections caused by P. psidii on native, naturalized, and cultivated Myrtaceae in Hawai`i.

Host range of Caloptilia triadicae (Lepidoptera: Gracillariidae): an adventive herbivore of Chinese tallowtree (Malpighiales: Euphorbiaceae)

USDA-ARS?s Scientific Manuscript database

In its native range the invasive weed, Rhodomyrtus tomentosa is host to a suite of herbivores. One, Strepsicrates sp. (Lepidoptera: Tortricidae) was collected in China in 2014, introduced under quarantine in Florida, USA and tested against related species to determine its host range and suitability ...

Reconstructing the gravitational field of the local Universe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Desmond, Harry; Ferreira, Pedro G.; Lavaux, Guilhem

Tests of gravity at the galaxy scale are in their infancy. As a first step to systematically uncovering the gravitational significance of galaxies, we map three fundamental gravitational variables – the Newtonian potential, acceleration and curvature – over the galaxy environments of the local Universe to a distance of approximately 200 Mpc. Our method combines the contributions from galaxies in an all-sky redshift survey, haloes from an N-body simulation hosting low-luminosity objects, and linear and quasi-linear modes of the density field. We use the ranges of these variables to determine the extent to which galaxies expand the scope of genericmore » tests of gravity and are capable of constraining specific classes of model for which they have special significance. In conclusion, we investigate the improvements afforded by upcoming galaxy surveys.« less

Reconstructing the gravitational field of the local Universe

DOE PAGES

Desmond, Harry; Ferreira, Pedro G.; Lavaux, Guilhem; ...

2017-11-25

Tests of gravity at the galaxy scale are in their infancy. As a first step to systematically uncovering the gravitational significance of galaxies, we map three fundamental gravitational variables – the Newtonian potential, acceleration and curvature – over the galaxy environments of the local Universe to a distance of approximately 200 Mpc. Our method combines the contributions from galaxies in an all-sky redshift survey, haloes from an N-body simulation hosting low-luminosity objects, and linear and quasi-linear modes of the density field. We use the ranges of these variables to determine the extent to which galaxies expand the scope of genericmore » tests of gravity and are capable of constraining specific classes of model for which they have special significance. In conclusion, we investigate the improvements afforded by upcoming galaxy surveys.« less

A PR-1-like Protein of Fusarium oxysporum Functions in Virulence on Mammalian Hosts*

PubMed Central

Prados-Rosales, Rafael C.; Roldán-Rodríguez, Raquel; Serena, Carolina; López-Berges, Manuel S.; Guarro, Josep; Martínez-del-Pozo, Álvaro; Di Pietro, Antonio

2012-01-01

The pathogenesis-related PR-1-like protein family comprises secreted proteins from the animal, plant, and fungal kingdoms whose biological function remains poorly understood. Here we have characterized a PR-1-like protein, Fpr1, from Fusarium oxysporum, an ubiquitous fungal pathogen that causes vascular wilt disease on a wide range of plant species and can produce life-threatening infections in immunocompromised humans. Fpr1 is secreted and proteolytically processed by the fungus. The fpr1 gene is required for virulence in a disseminated immunodepressed mouse model, and its function depends on the integrity of the proposed active site of PR-1-like proteins. Fpr1 belongs to a gene family that has expanded in plant pathogenic Sordariomycetes. These results suggest that secreted PR-1-like proteins play important roles in fungal pathogenicity. PMID:22553200

[Wellness holidays--wholesome wish or one-sided reality].

PubMed

Müller, H; Kaufmann, E L

2001-04-01

The term wellness is widely used in European tourism. The principal observations regarding the wellness industry concern an expanding supply of and an insufficiently researched demand for wellness programs. The quality dimension of wellness services is increasingly becoming the decisive competitive factor. For this reason quality management plays an important role. Market research shows that average 3- to 5-star hotels provide fairly comprehensive wellness facilities. Wellness hotels should therefore specialize in health information, individual care and a wide range of cultural and relaxation programs. Although the same hotel can host cure and wellness guests at the same time, these two segments have to be considered separately when deciding on the marketing strategy. We therefore assume that wellness is pursued solely by 'healthy' people, the prime aim being prevention. 'Normal cure guests' aim to heal their illness.

Host density drives the postglacial migration of the tree parasite, Epifagus virginiana.

PubMed

Tsai, Yi-Hsin Erica; Manos, Paul S

2010-09-28

To survive changes in climate, successful species shift their geographic ranges to remain in suitable habitats. For parasites and other highly specialized species, distributional changes not only are dictated by climate but can also be engineered by their hosts. The extent of host control on parasite range expansion is revealed through comparisons of host and parasite migration and demographic histories. However, understanding the codistributional history of entire forest communities is complicated by challenges in synthesizing datasets from multiple interacting species of differing datatypes. Here we integrate genetic and fossil pollen datasets from a host-parasite pair; specifically, the population structure of the parasitic plant (Epifagus virginiana) was compared with both its host (Fagus grandifolia) genetic patterns and abundance data from the paleopollen record of the last 21,000 y. Through tests of phylogeographic structure and spatial linear regression models we find, surprisingly, host range changes had little effect on the parasite's range expansion and instead host density is the main driver of parasite spread. Unlike other symbionts that have been used as proxies to track their host's movements, this parasite's migration routes are incongruent with the host and instead reflect the greater importance of host density in this community's assembly. Furthermore, these results confirm predictions of disease ecological models regarding the role of host density in the spread of pathogens. Due to host density constraints, highly specialized species may have low migration capacities and long lag times before colonization of new areas.

Codon optimization underpins generalist parasitism in fungi

PubMed Central

Badet, Thomas; Peyraud, Remi; Mbengue, Malick; Navaud, Olivier; Derbyshire, Mark; Oliver, Richard P; Barbacci, Adelin; Raffaele, Sylvain

2017-01-01

The range of hosts that parasites can infect is a key determinant of the emergence and spread of disease. Yet, the impact of host range variation on the evolution of parasite genomes remains unknown. Here, we show that codon optimization underlies genome adaptation in broad host range parasites. We found that the longer proteins encoded by broad host range fungi likely increase natural selection on codon optimization in these species. Accordingly, codon optimization correlates with host range across the fungal kingdom. At the species level, biased patterns of synonymous substitutions underpin increased codon optimization in a generalist but not a specialist fungal pathogen. Virulence genes were consistently enriched in highly codon-optimized genes of generalist but not specialist species. We conclude that codon optimization is related to the capacity of parasites to colonize multiple hosts. Our results link genome evolution and translational regulation to the long-term persistence of generalist parasitism. DOI: http://dx.doi.org/10.7554/eLife.22472.001 PMID:28157073

The Mega-MUSCLES HST Treasury Survey

NASA Astrophysics Data System (ADS)

Froning, Cynthia S.; France, Kevin; Loyd, R. O. Parke; Youngblood, Allison; Brown, Alexander; Schneider, Christian; Berta-Thompson, Zachory; Kowalski, Adam

2018-01-01

JWST will be able to observe the atmospheres of rocky planets transiting nearby M dwarfs. A few such planets are already known (around GJ1132, Proxima Cen, and Trappist-1) and TESS is predicted to find many more, including ~14 habitable zone planets. To interpret observations of these exoplanets' atmospheres, we must understand the high-energy SED of their host stars: X-ray/EUV irradiation can erode a planet's gaseous envelope and FUV/NUV-driven photochemistry shapes an atmosphere's molecular abundances, including potential biomarkers like O2, O3, and CH4. Our MUSCLES Treasury Survey (Cycles 19+22) used Hubble/COS+STIS UV observations with contemporaneous X-ray and ground-based data to construct complete SEDs for 11 low-mass exoplanet hosts. MUSCLES is the most widely used database for early-M and K dwarf (>0.3 M_sun) irradiance spectra and has supported a wide range of atmospheric stability and biomarker modeling work. However, TESS will find most of its habitable planets transiting stars less massive than this, and these will be the planets to characterize with JWST. Here, we introduce the Mega-MUSCLES project, an approved HST Cycle 25 Treasury program. Following on the successful MUSCLES survey, Mega-MUSCLES will expand our target list to focus on: (a) new M dwarf exoplanet hosts with varying properties; (b) reference M dwarfs below 0.3 solar masses that may be used as proxies for M dwarf planet hosts discovered after HST's lifetime; and (c) more rapidly rotating stars of GJ1132's mass to probe XUV evolution over gigayear timescales. We will also gather the first panchromatic SEDs of rocky planet hosts GJ1132 and Trappist-1. Here, we present an overview of the Mega-MUSCLES motivation, targets list, and status of the survey and show how it extends proven methods to a key new sample of stars, upon which critically depends the long-term goal of studying habitable planet atmospheres with JWST and beyond.

Molecular Investigations of Bacteroides as Microbial Source Tracking Tools in Southeast Louisiana Watersheds

NASA Astrophysics Data System (ADS)

Schulz, C. J.; Childers, G. W.; Engel, A. S.

2006-12-01

Microbial Source Tracking (MST) is a developing field that is gaining increased attention. MST refers to a host of techniques that discriminates among the origins of fecal material found in natural waters from different sources (e.g. human, livestock, and wildlife) by using microbial indicator species with specificity to only certain host organisms. The development of species-specific molecular markers would allow for better evaluation of public health risks and tracking of nutrient sources impacting a watershed. Although several MST methods have been reported with varying levels of success, few offer general applicability for natural waters due to spatial and temporal constraints associated with these methods. One group of molecular MST markers that show promise for broad environmental applications are molecular 16S rDNA probes for Bacteroides. This method is based on 16S rDNA detection directly from environmental samples without the need for a preliminary cultivation step. In this study we have expanded previous sampling efforts to compile a database of over 1000 partial 16S rRNA Bacteroides genes retrieved from the fecal material of 15 different host species (human, cat, dog, pig, kangaroo). To characterize survival of Bacteroides outside of the host, survival time of the Bacteroides marker was compared to that of E.coli under varying natural environmental conditions (temperature and salinity). Bacteroides displayed a survival curve with shouldering and tailing similar to that of E.coli, but log reduction times differed with treatment. In summary, MST marker stability was identified within host species and the overall Bacteroides community structure correlated to host diet, suggesting that detection of a Bacteroides community could confidently identify fecal contamination point sources. Natural water samples from southeast Louisiana were collected for MST including the Tangipahoa River watershed where the source of fecal contamination has been hotly debated. The Bacteroides tool repeatedly demonstrated the presence of cattle related Bacteroides markers and the absence of human markers.This study is now being expanded to include the entire Lake Pontchartrain Basin.

The potential for host switching via ecological fitting in the emerald ash borer-host plant system.

PubMed

Cipollini, Don; Peterson, Donnie L

2018-02-27

The traits used by phytophagous insects to find and utilize their ancestral hosts can lead to host range expansions, generally to closely related hosts that share visual and chemical features with ancestral hosts. Host range expansions often result from ecological fitting, which is the process whereby organisms colonize and persist in novel environments, use novel resources, or form novel associations with other species because of the suites of traits that they carry at the time they encounter the novel environment. Our objective in this review is to discuss the potential and constraints on host switching via ecological fitting in emerald ash borer, Agrilus planipennis, an ecologically and economically important invasive wood boring beetle. Once thought of as an ash (Fraxinus spp.) tree specialist, recent studies have revealed a broader potential host range than was expected for this insect. We discuss the demonstrated host-use capabilities of this beetle, as well as the potential for and barriers to the adoption of additional hosts by this beetle. We place our observations in the context of biochemical mechanisms that mediate the interaction of these beetles with their host plants and discuss whether evolutionary host shifts are a possible outcome of the interaction of this insect with novel hosts.

The role of epigenetics in host-parasite coevolution: lessons from the model host insects Galleria mellonella and Tribolium castaneum.

PubMed

Vilcinskas, Andreas

2016-08-01

Recent studies addressing experimental host-parasite coevolution and transgenerational immune priming in insects provide evidence for heritable shifts in host resistance or parasite virulence. These rapid reciprocal adaptations may thus be transferred to offspring generations by either genetic changes or mechanisms that do not involve changes in the germline DNA sequence. Epigenetic inheritance refers to changes in gene expression that are heritable across generations and mediated by epigenetic modifications passed from parents to offspring. Highlighting the role of epigenetics in host-parasite coevolution, this review discusses the involvement of DNA methylation, histone acetylation/deacetylation and microRNAs in the interactions between bacterial or fungal parasites and model host insects such as the greater wax moth Galleria mellonella and the red flour beetle Tribolium castaneum. These epigenetic mechanisms are thought to participate in generation-spanning transcriptional reprogramming in the host insect, often linking immunity with developmentally related gene expression and contributing to the heredity of acquired adaptations. It is proposed that the interactions during host-parasite coevolution can therefore be expanded beyond reciprocal genetic changes to include reciprocal epigenetic changes. Epigenetics is thus a promising and prospering field in the context of host-parasite coevolution. Copyright © 2016 The Author. Published by Elsevier GmbH.. All rights reserved.

Evolutionary interpretations of mycobacteriophage biodiversity and host-range through the analysis of codon usage bias.

PubMed

Esposito, Lauren A; Gupta, Swati; Streiter, Fraida; Prasad, Ashley; Dennehy, John J

2016-10-01

In an genomics course sponsored by the Howard Hughes Medical Institute (HHMI), undergraduate students have isolated and sequenced the genomes of more than 1,150 mycobacteriophages, creating the largest database of sequenced bacteriophages able to infect a single host, Mycobacterium smegmatis , a soil bacterium. Genomic analysis indicates that these mycobacteriophages can be grouped into 26 clusters based on genetic similarity. These clusters span a continuum of genetic diversity, with extensive genomic mosaicism among phages in different clusters. However, little is known regarding the primary hosts of these mycobacteriophages in their natural habitats, nor of their broader host ranges. As such, it is possible that the primary host of many newly isolated mycobacteriophages is not M. smegmatis , but instead a range of closely related bacterial species. However, determining mycobacteriophage host range presents difficulties associated with mycobacterial cultivability, pathogenicity and growth. Another way to gain insight into mycobacteriophage host range and ecology is through bioinformatic analysis of their genomic sequences. To this end, we examined the correlations between the codon usage biases of 199 different mycobacteriophages and those of several fully sequenced mycobacterial species in order to gain insight into the natural host range of these mycobacteriophages. We find that UPGMA clustering tends to match, but not consistently, clustering by shared nucleotide sequence identify. In addition, analysis of GC content, tRNA usage and correlations between mycobacteriophage and mycobacterial codon usage bias suggests that the preferred host of many clustered mycobacteriophages is not M. smegmatis but other, as yet unknown, members of the mycobacteria complex or closely allied bacterial species.

Evolutionary interpretations of mycobacteriophage biodiversity and host-range through the analysis of codon usage bias

PubMed Central

Esposito, Lauren A.; Gupta, Swati; Streiter, Fraida; Prasad, Ashley

2016-01-01

In an genomics course sponsored by the Howard Hughes Medical Institute (HHMI), undergraduate students have isolated and sequenced the genomes of more than 1,150 mycobacteriophages, creating the largest database of sequenced bacteriophages able to infect a single host, Mycobacterium smegmatis, a soil bacterium. Genomic analysis indicates that these mycobacteriophages can be grouped into 26 clusters based on genetic similarity. These clusters span a continuum of genetic diversity, with extensive genomic mosaicism among phages in different clusters. However, little is known regarding the primary hosts of these mycobacteriophages in their natural habitats, nor of their broader host ranges. As such, it is possible that the primary host of many newly isolated mycobacteriophages is not M. smegmatis, but instead a range of closely related bacterial species. However, determining mycobacteriophage host range presents difficulties associated with mycobacterial cultivability, pathogenicity and growth. Another way to gain insight into mycobacteriophage host range and ecology is through bioinformatic analysis of their genomic sequences. To this end, we examined the correlations between the codon usage biases of 199 different mycobacteriophages and those of several fully sequenced mycobacterial species in order to gain insight into the natural host range of these mycobacteriophages. We find that UPGMA clustering tends to match, but not consistently, clustering by shared nucleotide sequence identify. In addition, analysis of GC content, tRNA usage and correlations between mycobacteriophage and mycobacterial codon usage bias suggests that the preferred host of many clustered mycobacteriophages is not M. smegmatis but other, as yet unknown, members of the mycobacteria complex or closely allied bacterial species. PMID:28348827

Genomic Variation, Host Range, and Infection Kinetics of Closely Related Cyanopodoviruses from New England Coastal Waters

NASA Astrophysics Data System (ADS)

Veglia, A. J.; Milford, C. R.; Marston, M.

2016-02-01

Viruses infecting marine Synechococcus are abundant in coastal marine environments and influence the community composition and abundance of their cyanobacterial hosts. In this study, we focused on the cyanopodoviruses which have smaller genomes and narrower host ranges relative to cyanomyoviruses. While previous studies have compared the genomes of diverse podoviruses, here we analyzed the genomic variation, host ranges, and infection kinetics of podoviruses within the same OTU. The genomes of fifty-five podoviral isolates from the coastal waters of New England were fully sequenced. Based on DNA polymerase gene sequences, these isolates fall into five discrete OTUs (termed RIP - Rhode Island Podovirus). Although all the isolates belonging to the same RIP have very similar DNA polymerase gene sequences (>98% sequence identity), differences in genome content, particularly in regions associated with tail fiber genes, were observed among isolates in the same RIP. Host range tests reveal variation both across and within RIPs. Notably within RIP1, isolates that had similar tail fiber regions also had similar host ranges. Isolates belonging to RIP4 do not contain the host-derived psbA photosynthesis gene, while isolates in the other four RIPs do possess a psbA gene. Nevertheless, infection kinetic experiments suggest that the latent period and burst size for RIP4 isolates are similar to RIP1 isolates. We are continuing to investigate the correlations among genome content, host range, and infection kinetics of isolates belonging to the same OTU. Our results to date suggest that there is substantial genomic variation within an OTU and that this variation likely influences cyanopodoviral - host interactions.

The ins and outs of phosphosignalling in Plasmodium: Parasite regulation and host cell manipulation.

PubMed

Carvalho, Teresa Gil; Morahan, Belinda; John von Freyend, Simona; Boeuf, Philippe; Grau, Georges; Garcia-Bustos, Jose; Doerig, Christian

2016-07-01

Signal transduction and kinomics have been rapidly expanding areas of investigation within the malaria research field. Here, we provide an overview of phosphosignalling pathways that operate in all stages of the Plasmodium life cycle. We review signalling pathways in the parasite itself, in the cells it invades, and in other cells of the vertebrate host with which it interacts. We also discuss the potential of these pathways as novel targets for antimalarial intervention. Copyright © 2016 Elsevier B.V. All rights reserved.

Asymmetrical Coexistence of Nosema ceranae and N. apis in Honey Bees

USDA-ARS?s Scientific Manuscript database

Globalization has provided opportunities for parasites/pathogens to cross geographic boundaries and expand to new hosts. Recent studies showed that Nosema ceranae, originally considered as a microsporidian parasite of Eastern honey bees, Apis ceranae, was the disease agent of Nosemosis in European ...

Gut Immune Maturation Depends on Colonization with a Host-Specific Microbiota

PubMed Central

Chung, Hachung; Pamp, Sünje J.; Hill, Jonathan A.; Surana, Neeraj K.; Edelman, Sanna M.; Troy, Erin B.; Reading, Nicola C.; Villablanca, Eduardo J.; Wang, Sen; Mora, Jorge R.; Umesaki, Yoshinori; Mathis, Diane; Benoist, Christophe; Relman, David A.; Kasper, Dennis L.

2012-01-01

SUMMARY Gut microbial induction of host immune maturation exemplifies host-microbe mutualism. We colonized germ-free (GF) mice with mouse microbiota (MMb) or human microbiota (HMb) to determine whether small intestinal immune maturation depends on a coevolved host-specific microbiota. Gut bacterial numbers and phylum abundance were similar in MMb and HMb mice, but bacterial species differed, especially the Firmicutes. HMb mouse intestines had low levels of CD4+ and CD8+ T cells, few proliferating T cells, few dendritic cells, and low antimicrobial peptide expression–all characteristics of GF mice. Rat microbiota also failed to fully expand intestinal T cell numbers in mice. Colonizing GF or HMb mice with mouse-segmented filamentous bacteria (SFB) partially restored T cell numbers, suggesting that SFB and other MMb organisms are required for full immune maturation in mice. Importantly, MMb conferred better protection against Salmonella infection than HMb. A host-specific microbiota appears to be critical for a healthy immune system. PMID:22726443

Synthesis, characterization and processing of active rare earth-doped chalcohalide glasses

NASA Astrophysics Data System (ADS)

Debari, Roberto Mauro

Applications for infrared-transmitting non-oxide glass fibers span a broad range of topics. They can be used in the military, the medical field, telecommunications, and even in agriculture. Rare earth ions are used as dopants in these glasses in order to stimulate emissions in the infrared spectral region. In order to extend the host glass transmission further into the infrared, selenium atoms were substituted for sulfur in the established Ge-S-I chalcohalide glass system and the fundamental properties of these latter glasses were explored. Over 30 different compositions in the Ge-Se-I glass system were investigated as to their thermal and optical properties. The resulting optimum host with a composition of Ge15Se80I5 has a broad transmission range from 0.7 mum to 17.0 mum and a high working range over 145°C. The host glass also exhibited a Tg of 125°C, making rotational casting of a cladding tube for rod-and-tube fiberization a possibility. The base glass was doped with 1000 to 4000 ppm/wt of erbium, dysprosium, or neodymium. When doped with Er3+-ions, absorptions at 1.54 mum and 3.42 mum were observed. Nd3+-doping resulted in an absorption peak near 4.24 mum and Dy3+ ions caused absorption at 1.30 mum. Fluorescence emissions were found for neodymium at 1.396 mum with a FWHM of 74 nm, and for dysprosium at 1.145 mum with a FWHM of 75 nm, at 1.360 mum with a FWHM of 98 rim and at 1.674 mum with a FWHM of 60 nm. High optical quality tubes of the host glass could be formed using rotational casting in silica ampoules. Glass tubes, 4 to 6 cm long with a 1 cm outer diameter and a tailored inner-hole diameter ranging from 0.4 to 0.6 cm could be synthesized by this process with excellent dimensional tolerances around the circumference as well as along the length. A preform of this size provided 25 continuous meters of unclad fiber with diameters ranging from 140 to 200 mum. A UV-curable acrylate cladding was applied via an external coating cup. An x-ray analysis of the resulting fiber verified the constituents of the fiber. Due to tradeoffs between thermal properties, optical properties and rare earth solubility, the Ge-Se-I glass system must still be optimized prior to use as an active fiber device. Nevertheless, the viability of this host system has been demonstrated in this investigation. Some very promising advantages to adding halides to chalcogenide glass systems have been confirmed, including the tailoring of glass transition temperatures, enhancement of rare earth solubility, expanded fluorescence emissions in the IR, and suppression of some impurity absorption bands. Also, the potential for rod-and-tube fiberization utilizing the rotational casting method for tube synthesis has been established along with its resulting pristine core-clad interface. This research provides a foundation for active fiber device applications in the 2 to 10 mum spectral region.

INTEGRATING PARASITES AND PATHOGENS INTO THE STUDY OF GEOGRAPHIC RANGE LIMITS.

PubMed

Bozick, Brooke A; Real, Leslie A

2015-12-01

The geographic distributions of all species are limited, and the determining factors that set these limits are of fundamental importance to the fields of ecology and evolutionary biology. Plant and animal ranges have been of primary concern, while those of parasites, which represent much of the Earth's biodiversity, have been neglected. Here, we review the determinants of the geographic ranges of parasites and pathogens, and explore how parasites provide novel systems with which to investigate the ecological and evolutionary processes governing host/parasite spatial distributions. Although there is significant overlap in the causative factors that determine range borders of parasites and free-living species, parasite distributions are additionally constrained by the geographic range and ecology of the host species' population, as well as by evolutionary factors that promote host-parasite coevolution. Recently, parasites have been used to infer population demographic and ecological information about their host organisms and we conclude that this strategy can be further exploited to understand geographic range limitations of both host and parasite populations.

Computational approaches for discovery of common immunomodulators in fungal infections: towards broad-spectrum immunotherapeutic interventions

PubMed Central

2013-01-01

Background Fungi are the second most abundant type of human pathogens. Invasive fungal pathogens are leading causes of life-threatening infections in clinical settings. Toxicity to the host and drug-resistance are two major deleterious issues associated with existing antifungal agents. Increasing a host’s tolerance and/or immunity to fungal pathogens has potential to alleviate these problems. A host’s tolerance may be improved by modulating the immune system such that it responds more rapidly and robustly in all facets, ranging from the recognition of pathogens to their clearance from the host. An understanding of biological processes and genes that are perturbed during attempted fungal exposure, colonization, and/or invasion will help guide the identification of endogenous immunomodulators and/or small molecules that activate host-immune responses such as specialized adjuvants. Results In this study, we present computational techniques and approaches using publicly available transcriptional data sets, to predict immunomodulators that may act against multiple fungal pathogens. Our study analyzed data sets derived from host cells exposed to five fungal pathogens, namely, Alternaria alternata, Aspergillus fumigatus, Candida albicans, Pneumocystis jirovecii, and Stachybotrys chartarum. We observed statistically significant associations between host responses to A. fumigatus and C. albicans. Our analysis identified biological processes that were consistently perturbed by these two pathogens. These processes contained both immune response-inducing genes such as MALT1, SERPINE1, ICAM1, and IL8, and immune response-repressing genes such as DUSP8, DUSP6, and SPRED2. We hypothesize that these genes belong to a pool of common immunomodulators that can potentially be activated or suppressed (agonized or antagonized) in order to render the host more tolerant to infections caused by A. fumigatus and C. albicans. Conclusions Our computational approaches and methodologies described here can now be applied to newly generated or expanded data sets for further elucidation of additional drug targets. Moreover, identified immunomodulators may be used to generate experimentally testable hypotheses that could help in the discovery of broad-spectrum immunotherapeutic interventions. All of our results are available at the following supplementary website: http://bioinformatics.cs.vt.edu/~murali/supplements/2013-kidane-bmc PMID:24099000

Understanding the biology of ex vivo-expanded CD8 T cells for adoptive cell therapy: role of CD62L.

PubMed

Díaz-Montero, C Marcela; Zidan, Abdel-Aziz; Pallin, Maria F; Anagnostopoulos, Vasileios; Salem, Mohamed L; Wieder, Eric; Komanduri, Krishna; Montero, Alberto J; Lichtenheld, Mathias G

2013-12-01

CD62L governs the circulation of CD8(+) T cells between lymph nodes and peripheral tissues, whereby the expression of CD62L by CD8(+) T cells promotes their recirculation through lymph nodes. As such, CD62L participates in the fate of adoptively transferred CD8(+) T cells and may control their effectiveness for cancer immunotherapy, including settings in which host preconditioning results in the acute lymphopenia-induced proliferation of the transferred cells. Indeed, previous studies correlated CD62L expression by donor CD8(+) cells with the success rate of adoptive cell therapy (ACT). Here, we analyzed the functions and fate of ex vivo-activated, tumor-specific CD62L(-/-) CD8(+) T cells in a mouse melanoma model for ACT. Unexpectedly, we observed that CD62L(-/-) CD8(+) T cells were functionally indistinguishable from CD62L(+/+) CD8(+) T cells, i.e., both greatly expanded in cyclophosphamide preconditioned animals, controlled subcutaneously and hematogenously spreading tumors, and generated anti-tumor-specific CD8(+) T cell memory. Moreover, even in hosts with rudimentary secondary lymphoid organs (LT(-/-) animals), CD8(+) T cells with and without CD62L expanded equivalently to those adoptively transferred into wild-type animals. These results put into question the utility of CD62L as a predictive biomarker for the efficacy of ex vivo-expanded T cells after ACT in lymphopenic conditions and also offer new insights into the homing, engraftment, and memory generation of adoptively transferred ex vivo-activated CD8(+) T cells.

Fulfillment of Koch’s postulates and partial host range of Septoria lepidii Desm., a fungal pathogen for potential biological control of hoary cress (Lepidium spp.)

USDA-ARS?s Scientific Manuscript database

We have fulfilled Koch’s postulates and conducted host range tests with Septoria lepidii Desm. on five geographical accessions of hoary cress. Host range results showed the fungus specific to Lepidium spp. and damaging to hoary cress. This fungus is potentially an important biological control agent ...

Development of an aggressive bark beetle on novel hosts: Implications for outbreaks in an invaded range

Treesearch

Derek W. Rosenberger; Robert C. Venette; Brian H. Aukema; Jörg Müller

2018-01-01

Some subcortical insects have devastating effects on native tree communities in new ranges, despite benign interactions with their historical hosts. Examples of how insects, aggressive in their native habitat might respond in novel host environs are less common. One aggressive tree-killing insect undergoing a dramatic range shift is the mountain pine beetle (...

Host and ecology both play a role in shaping distribution of digenean parasites of New Zealand whelks (Gastropoda: Buccinidae: Cominella).

PubMed

Donald, Kirsten M; Spencer, Hamish G

2016-08-01

Digenean parasites infecting four Cominella whelk species (C. glandiformis, C. adspersa, C. maculosa and C. virgata), which inhabit New Zealand's intertidal zone, were analysed using molecular techniques. Mitochondrial 16S and cytochrome oxidase 1 (COI) and nuclear rDNA ITS1 sequences were used to infer phylogenetic relationships amongst digenea. Host species were parasitized by a diverse range of digenea (Platyhelminthes, Trematoda), representing seven families: Echinostomatidae, Opecoelidae, Microphallidae, Strigeidae and three, as yet, undetermined families A, B and C. Each parasite family infected between one and three host whelk species, and infection levels were typically low (average infection rates ranged from 1·4 to 3·6%). Host specificity ranged from highly species-specific amongst the echinostomes, which were only ever observed infecting C. glandiformis, to the more generalist opecoelids and strigeids, which were capable of infecting three out of four of the Cominella species analysed. Digeneans displayed a highly variable geographic range; for example, echinostomes had a large geographic range stretching the length of New Zealand, from Northland to Otago, whereas Family B parasites were restricted to fairly small areas of the North Island. Our results add to a growing body of research identifying wide ranges in both host specificity and geographic range amongst intertidal, multi-host parasite systems.

Copper tolerance and virulence in bacteria

PubMed Central

Ladomersky, Erik; Petris, Michael J.

2015-01-01

Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

Comparative Genomics and Host Resistance against Infectious Diseases

PubMed Central

Qureshi, Salman T.; Skamene, Emil

1999-01-01

The large size and complexity of the human genome have limited the identification and functional characterization of components of the innate immune system that play a critical role in front-line defense against invading microorganisms. However, advances in genome analysis (including the development of comprehensive sets of informative genetic markers, improved physical mapping methods, and novel techniques for transcript identification) have reduced the obstacles to discovery of novel host resistance genes. Study of the genomic organization and content of widely divergent vertebrate species has shown a remarkable degree of evolutionary conservation and enables meaningful cross-species comparison and analysis of newly discovered genes. Application of comparative genomics to host resistance will rapidly expand our understanding of human immune defense by facilitating the translation of knowledge acquired through the study of model organisms. We review the rationale and resources for comparative genomic analysis and describe three examples of host resistance genes successfully identified by this approach. PMID:10081670

Engineering terpene biosynthesis in Streptomyces for production of the advanced biofuel precursor bisabolene.

PubMed

Phelan, Ryan M; Sekurova, Olga N; Keasling, Jay D; Zotchev, Sergey B

2015-04-17

The past decade has witnessed a large influx of research toward the creation of sustainable, biologically derived fuels. While significant effort has been exerted to improve production capacity in common hosts, such as Escherichia coli or Saccharomyces cerevisiae, studies concerning alternate microbes comparatively lag. In an effort to expand the breadth of characterized hosts for fuel production, we map the terpene biosynthetic pathway in a model actinobacterium, Streptomyces venezuelae, and further alter secondary metabolism to afford the advanced biofuel precursor bisabolene. Leveraging information gained from study of the native isoprenoid pathway, we were able to increase bisabolene titer nearly 5-fold over the base production strain, more than 2 orders of magnitude greater than the combined terpene yield in the wild-type host. We also explored production on carbon sources of varying complexity to, notably, define this host as one able to perform consolidated bioprocessing.

Ecological host-range of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent of Dioscorea bulbifera L.

USDA-ARS?s Scientific Manuscript database

Open-field host-specificity testing assesses the host-range of a biological control agent in a setting that permits the agent to use its full complement of host-seeking behaviors. This form of testing, particularly when it includes a no-choice phase in which the target weed is killed, may provide th...

Demonstrating concepts of pathogenesis using effectors of Phytophthora infestans

USDA-ARS?s Scientific Manuscript database

Pathogenesis, or how pathogens cause disease, is an important concept in plant pathology. The study of pathogenesis in plant pathology has rapidly expanded and is now a significant portion of plant pathology research (especially research at the molecular level of host-pathogen interaction). With the...

Multi-Scale Clustering of Lyme Disease Risk at the Expanding Leading Edge of the Range of Ixodes scapularis in Canada.

PubMed

Ripoche, Marion; Lindsay, Leslie Robbin; Ludwig, Antoinette; Ogden, Nicholas H; Thivierge, Karine; Leighton, Patrick A

2018-03-27

Since its detection in Canada in the early 1990s, Ixodes scapularis , the primary tick vector of Lyme disease in eastern North America, has continued to expand northward. Estimates of the tick's broad-scale distribution are useful for tracking the extent of the Lyme disease risk zone; however, tick distribution may vary widely within this zone. Here, we investigated I. scapularis nymph distribution at three spatial scales across the Lyme disease emergence zone in southern Quebec, Canada. We collected ticks and compared the nymph densities among different woodlands and different plots and transects within the same woodland. Hot spot analysis highlighted significant nymph clustering at each spatial scale. In regression models, nymph abundance was associated with litter depth, humidity, and elevation, which contribute to a suitable habitat for ticks, but also with the distance from the trail and the type of trail, which could be linked to host distribution and human disturbance. Accounting for this heterogeneous nymph distribution at a fine spatial scale could help improve Lyme disease management strategies but also help people to understand the risk variation around them and to adopt appropriate behaviors, such as staying on the trail in infested parks to limit their exposure to the vector and associated pathogens.

Multi-Scale Clustering of Lyme Disease Risk at the Expanding Leading Edge of the Range of Ixodes scapularis in Canada

PubMed Central

Lindsay, Leslie Robbin; Ludwig, Antoinette; Ogden, Nicholas H.; Thivierge, Karine; Leighton, Patrick A.

2018-01-01

Since its detection in Canada in the early 1990s, Ixodes scapularis, the primary tick vector of Lyme disease in eastern North America, has continued to expand northward. Estimates of the tick’s broad-scale distribution are useful for tracking the extent of the Lyme disease risk zone; however, tick distribution may vary widely within this zone. Here, we investigated I. scapularis nymph distribution at three spatial scales across the Lyme disease emergence zone in southern Quebec, Canada. We collected ticks and compared the nymph densities among different woodlands and different plots and transects within the same woodland. Hot spot analysis highlighted significant nymph clustering at each spatial scale. In regression models, nymph abundance was associated with litter depth, humidity, and elevation, which contribute to a suitable habitat for ticks, but also with the distance from the trail and the type of trail, which could be linked to host distribution and human disturbance. Accounting for this heterogeneous nymph distribution at a fine spatial scale could help improve Lyme disease management strategies but also help people to understand the risk variation around them and to adopt appropriate behaviors, such as staying on the trail in infested parks to limit their exposure to the vector and associated pathogens. PMID:29584627

Rainfall and temperatures changes have confounding impacts on Phytophthora cinnamomi occurrence risk in the southwestern USA under climate change scenarios.

PubMed

Thompson, Sally E; Levin, Simon; Rodriguez-Iturbe, Ignacio

2014-04-01

Global change will simultaneously impact many aspects of climate, with the potential to exacerbate the risks posed by plant pathogens to agriculture and the natural environment; yet, most studies that explore climate impacts on plant pathogen ranges consider individual climatic factors separately. In this study, we adopt a stochastic modeling approach to address multiple pathways by which climate can constrain the range of the generalist plant pathogen Phytophthora cinnamomi (Pc): through changing winter soil temperatures affecting pathogen survival; spring soil temperatures and thus pathogen metabolic rates; and changing spring soil moisture conditions and thus pathogen growth rates through host root systems. We apply this model to the southwestern USA for contemporary and plausible future climate scenarios and evaluate the changes in the potential range of Pc. The results indicate that the plausible range of this pathogen in the southwestern USA extends over approximately 200,000 km(2) under contemporary conditions. While warming temperatures as projected by the IPCC A2 and B1 emissions scenarios greatly expand the range over which the pathogen can survive winter, projected reductions in spring rainfall reduce its feasible habitat, leading to spatially complex patterns of changing risk. The study demonstrates that temperature and rainfall changes associated with possible climate futures in the southwestern USA have confounding impacts on the range of Pc, suggesting that projections of future pathogen dynamics and ranges should account for multiple pathways of climate-pathogen interaction. © 2014 John Wiley & Sons Ltd.

NGA-West2 Empirical Fourier Model for Active Crustal Regions to Generate Regionally Adjustable Response Spectra

NASA Astrophysics Data System (ADS)

Bora, S. S.; Cotton, F.; Scherbaum, F.; Kuehn, N. M.

2016-12-01

Adjustment of median ground motion prediction equations (GMPEs) from data-rich (host) regions to data-poor regions (target) is one of major challenges that remains with the current practice of engineering seismology and seismic hazard analysis. Fourier spectral representation of ground motion provides a solution to address the problem of adjustment that is physically transparent and consistent with the concepts of linear system theory. Also, it provides a direct interface to appreciate the physically expected behavior of seismological parameters on ground motion. In the present study, we derive an empirical Fourier model for computing regionally adjustable response spectral ordinates based on random vibration theory (RVT) from shallow crustal earthquakes in active tectonic regions, following the approach of Bora et al. (2014, 2015). , For this purpose, we use an expanded NGA-West2 database with M 3.2—7.9 earthquakes at distances ranging from 0 to 300 km. A mixed-effects regression technique is employed to further explore various components of variability. The NGA-West2 database expanded over a wide magnitude range provides a better understanding (and constraint) of source scaling of ground motion. The large global volume of the database also allows investigating regional patterns in distance-dependent attenuation (i.e., geometrical spreading and inelastic attenuation) of ground motion as well as in the source parameters (e.g., magnitude and stress drop). Furthermore, event-wise variability and its correlation with stress parameter are investigated. Finally, application of the derived Fourier model in generating adjustable response spectra will be shown.

Distributional Patterns of Pseudacteon Associated with the Solenopsis saevissima Complex in South America

PubMed Central

Patrock, Richard J. W.; Porter, Sanford D.; Gilbert, Lawrence E.; Folgarait, Patricia J.

2009-01-01

Classical biological control efforts against imported fire ants have largely involved the use of Pseudacteon parasitoids. To facilitate further exploration for species and population biotypes a database of collection records for Pseudacteon species was organized, including those from the literature and other sources. These data were then used to map the geographical ranges of species associated with the imported fire ants in their native range in South America. In addition, we found geographical range metrics for all species in the genus and related these metrics to latitude and host use. Approximately equal numbers of Pseudacteon species were found in temperate and tropical regions, though the majority of taxa found only in temperate areas were found in the Northern Hemisphere. No significant differences in sizes of geographical ranges were found between Pseudacteon associated with the different host complexes of fire ants despite the much larger and systemic collection effort associated with the S. saevissima host group. The geographical range of the flies was loosely associated with both the number of hosts and the geographical range of their hosts. Pseudacteon with the most extensive ranges had either multiple hosts or hosts with broad distributions. Mean species richnesses of Pseudacteon in locality species assemblages associated with S. saevissima complex ants was 2.8 species, but intensively sampled locations were usually much higher. Possible factors are discussed related to variation in the size of geographical range, and areas in southern South America are outlined that are likely to have been under-explored for Pseudacteon associated with imported fire ants. PMID:20050779

Development and Validation of a Microtiter Plate-Based Assay for Determination of Bacteriophage Host Range and Virulence.

PubMed

Xie, Yicheng; Wahab, Laith; Gill, Jason J

2018-04-12

Bacteriophages, which are the natural predators of bacteria, have re-emerged as an attractive alternative to combat antibiotic resistant bacteria. Phages are highly specific at the species and strain level and measurement of the phage host range plays an important role in utilizing the phage as antimicrobials. The most common method for phage host range determination has been to spot phage lysates on soft agar overlays and observe plaque formation. In this study, a liquid culture-based assay was developed in a 96-well microtiter plate format to measure the phage host range and virulence for a collection of 15 Salmonella phages against a panel of 20 Salmonella strains representing 11 serovars. This method was compared to a traditional spot method. The majority of the host range results from two methods were in agreement including in cases where a bacterial strain was insensitive to the phage. Each method produced a false-negative result in 19/300 (6%) of the measured phage-host combinations when compared to the other method. The spot method tended to indicate greater phage sensitivity than the microtiter assay even though direct comparisons of the response magnitude between the two methods is difficult since they operate on different mechanisms. The microtiter plate assay was able to provide data on both the phage host range and virulence in greater resolution in a high-throughput format.

Development and Validation of a Microtiter Plate-Based Assay for Determination of Bacteriophage Host Range and Virulence

PubMed Central

Xie, Yicheng; Wahab, Laith

2018-01-01

Bacteriophages, which are the natural predators of bacteria, have re-emerged as an attractive alternative to combat antibiotic resistant bacteria. Phages are highly specific at the species and strain level and measurement of the phage host range plays an important role in utilizing the phage as antimicrobials. The most common method for phage host range determination has been to spot phage lysates on soft agar overlays and observe plaque formation. In this study, a liquid culture-based assay was developed in a 96-well microtiter plate format to measure the phage host range and virulence for a collection of 15 Salmonella phages against a panel of 20 Salmonella strains representing 11 serovars. This method was compared to a traditional spot method. The majority of the host range results from two methods were in agreement including in cases where a bacterial strain was insensitive to the phage. Each method produced a false-negative result in 19/300 (6%) of the measured phage-host combinations when compared to the other method. The spot method tended to indicate greater phage sensitivity than the microtiter assay even though direct comparisons of the response magnitude between the two methods is difficult since they operate on different mechanisms. The microtiter plate assay was able to provide data on both the phage host range and virulence in greater resolution in a high-throughput format. PMID:29649135

Host selection and lethality of attacks by sea lampreys (Petromyzon marinus) in laboratory studies

USGS Publications Warehouse

Swink, William D.

2003-01-01

Parasitic-phase sea lampreys (Petromyzon marinus) are difficult to study in the wild. A series of laboratory studies (1984-1995) of single attacks on lake trout (Salvelinus namaycush), rainbow trout (Oncorhynchus mykiss), and burbot (Lota lota) examined host size selection; determined the effects of host size, host species, host strain, and temperature on host mortality; and estimated the weight of hosts killed per lamprey. Rainbow trout were more able and burbot less able to survive attacks than lake trout. Small sea lampreys actively selected the larger of two small hosts; larger sea lampreys attacked larger hosts in proportion to the hosts' body sizes, but actively avoided shorter hosts (a?? 600 mm) when larger were available. Host mortality was significantly less for larger (43-44%) than for smaller hosts (64%). However, the yearly loss of hosts per sea lamprey was less for small hosts (range, 6.8-14.2 kg per sea lamprey) than larger hosts (range, 11.4-19.3 kg per sea lamprey). Attacks at the lower of two temperature ranges (6.1-11.8A?C and 11.1-15.0A?C) did not significantly reduce the percentage of hosts killed (54% vs. 69%, p > 0.21), but longer attachment times at lower temperatures reduced the number of hosts attacked (33 vs. 45), and produced the lowest loss of hosts (6.6 kg per sea lamprey). Low temperature appeared to offset other factors that increase host mortality. Reanalysis of 789 attacks pooled from these studies, using forward stepwise logistic regression, also identified mean daily temperature as the dominant factor affecting host mortality. Observations in Lakes Superior, Huron, and Ontario support most laboratory results.

Large-scale maps of variable infection efficiencies in aquatic Bacteroidetes phage-host model systems: Variable phage-host infection interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holmfeldt, Karin; Solonenko, Natalie; Howard-Varona, Cristina

Microbes drive ecosystem functioning and their viruses modulate these impacts through mortality, gene transfer and metabolic reprogramming. Despite the importance of virus-host interactions and likely variable infection efficiencies of individual phages across hosts, such variability is seldom quantified. In this paper, we quantify infection efficiencies of 38 phages against 19 host strains in aquatic Cellulophaga (Bacteroidetes) phage-host model systems. Binary data revealed that some phages infected only one strain while others infected 17, whereas quantitative data revealed that efficiency of infection could vary 10 orders of magnitude, even among phages within one population. This provides a baseline for understanding andmore » modeling intrapopulation host range variation. Genera specific host ranges were also informative. For example, the Cellulophaga Microviridae, showed a markedly broader intra-species host range than previously observed in Escherichia coli systems. Further, one phage genus, Cba41, was examined to investigate nonheritable changes in plating efficiency and burst size that depended on which host strain it most recently infected. While consistent with host modification of phage DNA, no differences in nucleotide sequence or DNA modifications were detected, leaving the observation repeatable, but the mechanism unresolved. Overall, this study highlights the importance of quantitatively considering replication variations in studies of phage-host interactions.« less

Large-scale maps of variable infection efficiencies in aquatic Bacteroidetes phage-host model systems: Variable phage-host infection interactions

DOE PAGES

Holmfeldt, Karin; Solonenko, Natalie; Howard-Varona, Cristina; ...

2016-06-28

Microbes drive ecosystem functioning and their viruses modulate these impacts through mortality, gene transfer and metabolic reprogramming. Despite the importance of virus-host interactions and likely variable infection efficiencies of individual phages across hosts, such variability is seldom quantified. In this paper, we quantify infection efficiencies of 38 phages against 19 host strains in aquatic Cellulophaga (Bacteroidetes) phage-host model systems. Binary data revealed that some phages infected only one strain while others infected 17, whereas quantitative data revealed that efficiency of infection could vary 10 orders of magnitude, even among phages within one population. This provides a baseline for understanding andmore » modeling intrapopulation host range variation. Genera specific host ranges were also informative. For example, the Cellulophaga Microviridae, showed a markedly broader intra-species host range than previously observed in Escherichia coli systems. Further, one phage genus, Cba41, was examined to investigate nonheritable changes in plating efficiency and burst size that depended on which host strain it most recently infected. While consistent with host modification of phage DNA, no differences in nucleotide sequence or DNA modifications were detected, leaving the observation repeatable, but the mechanism unresolved. Overall, this study highlights the importance of quantitatively considering replication variations in studies of phage-host interactions.« less

Research Spotlight: Corals expanding poleward due to warming climate

NASA Astrophysics Data System (ADS)

Tretkoff, Ernie

2011-04-01

Corals are important organisms for ecosystems and are sensitive indicators of the effects of climate warming. While corals are bleaching and dying in tropical areas due to climate warming, a new study shows that in temperate areas they are expanding their range poleward as water temperatures increase. Yamano et al. used 80 years of records to study the range of corals around Japan. Sea surface temperatures have risen in these temperate areas during that time. They found that four of the nine species of coral they studied expanded their range northward since the 1930s, while none had its range shrink southward. The corals expanded northward as quickly as 14 kilometers per year. The study suggests that rapid modifications of temperate coastal ecosystems could be taking place. (Geophysical Research Letters, doi:10.1029/2010GL046474, 2011)

Vaccine Development against Zoonotic Hepatitis E Virus: Open Questions and Remaining Challenges

PubMed Central

Nan, Yuchen; Wu, Chunyan; Zhao, Qin; Sun, Yani; Zhang, Yan-Jin; Zhou, En-Min

2018-01-01

Hepatitis E virus (HEV) is a fecal-orally transmitted foodborne viral pathogen that causes acute hepatitis in humans and is responsible for hepatitis E outbreaks worldwide. Since the discovery of HEV as a zoonotic agent, this virus has been isolated from a variety of hosts with an ever-expanding host range. Recently, a subunit HEV vaccine developed for the prevention of human disease was approved in China, but is not yet available to the rest of the world. Meanwhile, notable progress and knowledge has been made and revealed in recent years to better understand HEV biology and infection, including discoveries of quasi-enveloped HEV virions and of a new function of the HEV-ORF3 product. However, the impact of these new findings on the development of a protective vaccine against zoonotic HEV infection requires further discussion. In this review, hallmark characteristics of HEV zoonosis, the history of HEV vaccine development, and recent discoveries in HEV virology are described. Moreover, special attention is focused on quasi-enveloped HEV virions and the potential role of the HEV-ORF3 product as antibody-neutralization target on the surface of quasi-enveloped HEV virions to provide new insights for the future development of improved vaccines against zoonotic HEV infection. PMID:29520257

Vaccine Development against Zoonotic Hepatitis E Virus: Open Questions and Remaining Challenges.

PubMed

Nan, Yuchen; Wu, Chunyan; Zhao, Qin; Sun, Yani; Zhang, Yan-Jin; Zhou, En-Min

2018-01-01

Hepatitis E virus (HEV) is a fecal-orally transmitted foodborne viral pathogen that causes acute hepatitis in humans and is responsible for hepatitis E outbreaks worldwide. Since the discovery of HEV as a zoonotic agent, this virus has been isolated from a variety of hosts with an ever-expanding host range. Recently, a subunit HEV vaccine developed for the prevention of human disease was approved in China, but is not yet available to the rest of the world. Meanwhile, notable progress and knowledge has been made and revealed in recent years to better understand HEV biology and infection, including discoveries of quasi-enveloped HEV virions and of a new function of the HEV-ORF3 product. However, the impact of these new findings on the development of a protective vaccine against zoonotic HEV infection requires further discussion. In this review, hallmark characteristics of HEV zoonosis, the history of HEV vaccine development, and recent discoveries in HEV virology are described. Moreover, special attention is focused on quasi-enveloped HEV virions and the potential role of the HEV-ORF3 product as antibody-neutralization target on the surface of quasi-enveloped HEV virions to provide new insights for the future development of improved vaccines against zoonotic HEV infection.

American Cutaneous Leishmaniasis in Panama: a historical review of entomological studies on anthropophilic Lutzomyia sand fly species

PubMed Central

2014-01-01

We review existing information on the epidemiology of American Cutaneous Leishmaniasis (ACL) in Panama, with emphasis on the bionomics of anthropophilic Lutzomyia sand fly species. Evidence from Panamanian studies suggests that there are six anthropophilic species in the country: Lutzomyia trapidoi, Lu. panamensis, Lu. gomezi, Lu. ylephiletor, Lu. sanguinaria and Lu. pessoana (Henceforth Lu. carrerai thula). In general, these taxa are abundant, widespread and feed opportunistically on their hosts, which make them potential transmitters of pathogens to a broad range of wildlife, domesticated animals and humans. Furthermore, nearly all man-biting species in Panama (with the exception of Lu. gomezi) expand demographically during the rainy season when transmission is likely higher due to elevated Leishmania infection rates in vector populations. Despite this, data on the distribution and prevalence of ACL suggest little influence of vector density on transmission intensity. Apart from Lu. trapidoi, anthropophilic species seem to be most active in the understory, but vertical stratification, as well as their opportunistic feeding behavior, could vary geographically. This in turn seems related to variation in host species composition and relative abundance across sites that have experienced different degrees of human alteration (e.g., deforestation) in leishmaniasis endemic regions of Panama. PMID:24886629

Echinococcus multilocularis in North America: the great unknown.

PubMed

Massolo, Alessandro; Liccioli, Stefano; Budke, Christine; Klein, Claudia

2014-01-01

Over the last decade, studies have begun to shed light on the distribution and genetic characterization of Echinococcus multilocularis, the causative agent of alveolar echinococcosis (AE), in North America. Recent findings indicate that the parasite is likely expanding its range in the central region of the United States and Canada and that invasions of European strains might have occurred. In our review, we present the available data on E. multilocularis infections in wild and domestic animals and humans in North America and emphasize the lack of knowledge on the distribution of the parasite in wild and domestic hosts. Furthermore, we stress the need to better understand the complexity of host communities and their roles in shaping the transmission and distribution of the parasite. We hypothesize that a lack of knowledge about AE by North American physicians might result in the misdiagnosis of cases and an underestimation of disease incidence. The endemic presence of the parasite in urban areas and a recent human case in Alberta, Canada, suggest that the scientific community may need to reconsider the local public health risks, re-assess past cases that might have been overlooked and increase surveillance efforts to identify new cases of human AE. © A. Massolo et al., published by EDP Sciences, 2014.

Zoonotic infections in Alaska: disease prevalence, potential impact of climate change and recommended actions for earlier disease detection, research, prevention and control.

PubMed

Hueffer, Karsten; Parkinson, Alan J; Gerlach, Robert; Berner, James

2013-01-01

Over the last 60 years, Alaska's mean annual temperature has increased by 1.6°C, more than twice the rate of the rest of the United States. As a result, climate change impacts are more pronounced here than in other regions of the United States. Warmer temperatures may allow some infected host animals to survive winters in larger numbers, increase their population and expand their range of habitation thus increasing the opportunity for transmission of infection to humans. Subsistence hunting and gathering activities may place rural residents of Alaska at a greater risk of acquiring zoonotic infections than urban residents. Known zoonotic diseases that occur in Alaska include brucellosis, toxoplasmosis, trichinellosis, giardiasis/cryptosporidiosis, echinococcosis, rabies and tularemia. Actions for early disease detection, research and prevention and control include: (1) determining baseline levels of infection and disease in both humans and host animals; (2) conducting more research to understand the ecology of infection in the Arctic environment; (3) improving active and passive surveillance systems for infection and disease in humans and animals; (4) improving outreach, education and communication on climate-sensitive infectious diseases at the community, health and animal care provider levels; and (5) improving coordination between public health and animal health agencies, universities and tribal health organisations.

Challenges in predicting climate and environmental effects on vector-borne disease episystems in a changing world.

PubMed

Tabachnick, W J

2010-03-15

Vector-borne pathogens cause enormous suffering to humans and animals. Many are expanding their range into new areas. Dengue, West Nile and Chikungunya have recently caused substantial human epidemics. Arthropod-borne animal diseases like Bluetongue, Rift Valley fever and African horse sickness pose substantial threats to livestock economies around the world. Climate change can impact the vector-borne disease epidemiology. Changes in climate will influence arthropod vectors, their life cycles and life histories, resulting in changes in both vector and pathogen distribution and changes in the ability of arthropods to transmit pathogens. Climate can affect the way pathogens interact with both the arthropod vector and the human or animal host. Predicting and mitigating the effects of future changes in the environment like climate change on the complex arthropod-pathogen-host epidemiological cycle requires understanding of a variety of complex mechanisms from the molecular to the population level. Although there has been substantial progress on many fronts the challenges to effectively understand and mitigate the impact of potential changes in the environment on vector-borne pathogens are formidable and at an early stage of development. The challenges will be explored using several arthropod-borne pathogen systems as illustration, and potential avenues to meet the challenges will be presented.

A new species of the rare endoparasitic copepod Entobius (Copepoda: Entobiidae) from Mexico with a key to the species of the genus.

PubMed

Suárez-Morales, Eduardo; Carrera-Parra, Luis F

2012-09-01

Abstract: In a study of the benthic polychaete fauna of the southern Gulf of Mexico and the Caribbean Sea, several specimens of the terebellid polychaete Scionides reticulata (Ehlers) were found to host endoparasitic copepods that represent an undescribed species of the rare cyclopoid genus Entobius Dogiel, 1948. The new species, E. scionides sp. n., can be distinguished from its congeners by a combination of characters including a genital region without constrictions, three-segmented antennules, a reduced antenna with a blunt terminal process, reduced ornamentation of endopods of legs 1-4 and its relatively small size (2.3-2.7 mm). It is the smallest species of the genus. Comments on immature females are also provided, but males of this species remain unknown. It has a high prevalence (53%) in populations of the terebellid S. reticulata in the southern Gulf of Mexico, but it is absent from the Caribbean. This is the first occurrence of this copepod genus in the Americas. The finding of the new species of Entobius in S. reticulata confirms the strict specificity of most members of the genus and expands the host range of this copepod genus. A key for the identification of the species of Entobius is provided.

Data Day to Day: building a community of expertise to address data skills gaps in an academic medical center

PubMed Central

Surkis, Alisa; LaPolla, Fred Willie Zametkin; Contaxis, Nicole; Read, Kevin B.

2017-01-01

Background The New York University Health Sciences Library data services team had developed educational material for research data management and data visualization and had been offering classes at the request of departments, research groups, and training programs, but many members of the medical center were unaware of these library data services. There were also indications of data skills gaps in these subject areas and other data-related topics. Case Presentation The data services team enlisted instructors from across the medical center with data expertise to teach in a series of classes hosted by the library. We hosted eight classes branded as a series called “Data Day to Day.” Seven instructors from four units in the medical center, including the library, taught the classes. A multipronged outreach approach resulted in high turnout. Evaluations indicated that attendees were very satisfied with the instruction, would use the skills learned, and were interested in future classes. Conclusions Data Day to Day met previously unaddressed data skills gaps. Collaborating with outside instructors allowed the library to serve as a hub for a broad range of data instruction and to raise awareness of library services. We plan to offer the series three times in the coming year with an expanding roster of classes. PMID:28377684

Attack and Success of Native and Exotic Parasitoids on Eggs of Halyomorpha halys in Three Maryland Habitats

PubMed Central

Herlihy, Megan V.; Talamas, Elijah J.; Weber, Donald C.

2016-01-01

Egg parasitoids of the exotic invasive brown marmorated stink bug, Halyomorpha halys (Stål), were investigated using lab-reared fresh (live) and frozen (killed) lab-reared sentinel egg masses deployed for 72h on foliage in three habitats—woods, orchard, and soybean field—in Maryland, USA, in summer 2014. Four native hymenopteran species, Telenomus podisi Ashmead (Scelionidae), Trissolcus euschisti (Ashmead) and Tr. brochymenae Ashmead (Scelionidae), and Anastatus reduvii (Howard) (Eupelmidae), developed and emerged from H. halys eggs. One exotic parasitoid, Trissolcus japonicus (Ashmead), emerged, providing the first known occurrence of this species in North America. Native parasitoids emerged from frozen eggs significantly more often than from fresh eggs (89.3% of egg masses and 98.1% of individual eggs), whereas the exotic Tr. japonicus did not show a similar difference, strongly suggesting adaptation to H. halys as a host by Tr. japonicus but not by the native species. Parasitoids were habitat-specific: all three Trissolcus species were significantly more likely to occur in the woods habitat, whereas Te. podisi was found exclusively in the soybean field. Further investigations are required to elucidate evolving host-parasitoid relationships, habitat specificity, and non-target effects of Tr. japonicus over the expanded range of H. halys in North America. PMID:26983012

An NMR Study of Microvoids in Polymers

NASA Technical Reports Server (NTRS)

Toy, James; Mattrix, Larry

1996-01-01

An understanding of polymer defect structures, like microvoids in polymeric matrices, is most crucial to their fabrication and application potential. In this project guest atoms are introduced into the microvoids in PMR-15 and NMR is used to determine microvoid sizes and locations. Xenon is a relatively inert probe that would normally not be found naturally in polymer or in NMR probe materials. There are two NMR active Xenon isotopes, Xe-129 and Xe-131. The Xe atom has a very high polarizability, which makes it sensitive to the intracrystalline environment of polymers. Interactions between the Xe atoms and the host matrix perturb and Xe electron cloud, deshielding the nuclei, and thereby expanding the range of the observed NMR chemical shifts. This chemical shift range which may be as large as 5000 ppm, permits subtle structural and chemical effects to be studied with high sensitivity. The Xe-129-NMR line shape has been found to vary in response to changes in the pore symmetry of the framework hosts in Zeolites and Clathrasil compounds. Before exposure to Xe gas, the PMR-15 samples were dried in a vacuum oven at 150 C for 48 hours. The samples were then exposed to Xe gas at 30 psi for 72 hours and sealed in glass tubes with 1 atmosphere of Xenon gas. Xenon gas at 1 atmosphere was used to tune up the spectrometer and to set up the appropriate NMR parameters. A series of spectra were obtained interspersed with applications of vacuum and heating to drive out the adsorbed Xe and determine the role of Xe-Xe interactions in the observed chemical shift.

Emergence of zoonotic arboviruses by animal trade and migration

PubMed Central

2010-01-01

Arboviruses are transmitted in nature exclusively or to a major extend by arthropods. They belong to the most important viruses invading new areas in the world and their occurrence is strongly influenced by climatic changes due to the life cycle of the transmitting vectors. Several arboviruses have emerged in new regions of the world during the last years, like West Nile virus (WNV) in the Americas, Usutu virus (USUV) in Central Europe, or Rift Valley fever virus (RVFV) in the Arabian Peninsula. In most instances the ways of introduction of arboviruses into new regions are not known. Infections acquired during stays in the tropics and subtropics are diagnosed with increasing frequency in travellers returning from tropical countries, but interestingly no attention is paid on accompanying pet animals or the hematophagous ectoparasites that may still be attached to them. Here we outline the known ecology of the mosquito-borne equine encephalitis viruses (WEEV, EEEV, and VEEV), WNV, USUV, RVFV, and Japanese Encephalitis virus, as well as Tick-Borne Encephalitis virus and its North American counterpart Powassan virus, and will discuss the most likely mode that these viruses could expand their respective geographical range. All these viruses have a different epidemiology as different vector species, reservoir hosts and virus types have adapted to promiscuous and robust or rather very fine-balanced transmission cycles. Consequently, these viruses will behave differently with regard to the requirements needed to establish new endemic foci outside their original geographical ranges. Hence, emphasis is given on animal trade and suitable ecologic conditions, including competent vectors and vertebrate hosts. PMID:20377873

Host-Plant Specialization Mediates the Influence of Plant Abundance on Host Use by Flower Head-Feeding Insects.

PubMed

Nobre, Paola A F; Bergamini, Leonardo L; Lewinsohn, Thomas M; Jorge, Leonardo R; Almeida-Neto, Mário

2016-02-01

Among-population variation in host use is a common phenomenon in herbivorous insects. The simplest and most trivial explanation for such variation in host use is the among-site variation in plant species composition. Another aspect that can influence spatial variation in host use is the relative abundance of each host-plant species compared to all available hosts. Here, we used endophagous insects that develop in flower heads of Asteraceae species as a study system to investigate how plant abundance influences the pattern of host-plant use by herbivorous insects with distinct levels of host-range specialization. Only herbivores recorded on three or more host species were included in this study. In particular, we tested two related hypotheses: 1) plant abundance has a positive effect on the host-plant preference of herbivorous insects, and 2) the relative importance of plant abundance to host-plant preference is greater for herbivorous species that use a wider range of host-plant species. We analyzed 11 herbivore species in 20 remnants of Cerrado in Southeastern Brazil. For 8 out of 11 herbivore species, plant abundance had a positive influence on host use. In contrast to our expectation, both the most specialized and the most generalist herbivores showed a stronger positive effect of plant species abundance in host use. Thus, we found evidence that although the abundance of plant species is a major factor determining the preferential use of host plants, its relative importance is mediated by the host-range specialization of herbivores.

Surveillance for antibodies to Leishmania spp. in dogs from Sri Lanka and India

USDA-ARS?s Scientific Manuscript database

The global distribution of leishmaniasis is rapidly expanding into new geographic regions. Dogs are the primary reservoir hosts for human visceral leishmaniasis (VL) caused by infection with Leishmania infantum. Natural infections with other Leishmania species can occur in dogs, but their role as re...

Professional Development for Occupational Specialist: Occupational Competency Testing. Final Report.

ERIC Educational Resources Information Center

Purdue Univ., Lafayette, IN.

The organization, scope, and activities of the Indiana Occupational Competency Testing Center were expanded to accommodate the requirements of the new Occupational Specialist Certificate for secondary vocational teacher credentialling. A pilot project involved three regional sites in the state. The director of the host area site acted as area…

Strategic Studies Quarterly. Volume 8, Number 4. Winter 2014

DTIC Science & Technology

2014-01-01

democratic gover - nance to the states of the area.’^’’ China has been active in developing infrastructure in Central Asia. For example, the China Road...drilling wells, expanding existing systems, and creating new ones.*^ • Agreements were made across a host of tourism , industrial, con- struction, and

Expanding soil health assessment methods for agricultural systems of the southern great plains

USDA-ARS?s Scientific Manuscript database

In agricultural systems, soil health (also referred as soil quality) is critical for sustainable production and ecosystem services. Soil health analyses dependent upon singular parameters fail to account for the host of interactions occurring within the soil ecosystem. Soil health is in flux with m...

Phytophthora ramorum tissue colonization studied with fluorescense microscopy

Treesearch

M. Riedel; S. Wagner; M. Gotz; L. Belbahri; F. Lefort; S. Werres

2009-01-01

The proceeding worldwide spread and the expanding host spectrum of P. ramorum has become a serious threat to natural plant communities. To encounter this threat detailed knowledge about infection pathways and tissue colonization is essential. To analyze these issues, histological studies of infected tissue with epifluorescence microscopy have been...

Host genetic variation impacts microbiome composition across human body sites.

PubMed

Blekhman, Ran; Goodrich, Julia K; Huang, Katherine; Sun, Qi; Bukowski, Robert; Bell, Jordana T; Spector, Timothy D; Keinan, Alon; Ley, Ruth E; Gevers, Dirk; Clark, Andrew G

2015-09-15

The composition of bacteria in and on the human body varies widely across human individuals, and has been associated with multiple health conditions. While microbial communities are influenced by environmental factors, some degree of genetic influence of the host on the microbiome is also expected. This study is part of an expanding effort to comprehensively profile the interactions between human genetic variation and the composition of this microbial ecosystem on a genome- and microbiome-wide scale. Here, we jointly analyze the composition of the human microbiome and host genetic variation. By mining the shotgun metagenomic data from the Human Microbiome Project for host DNA reads, we gathered information on host genetic variation for 93 individuals for whom bacterial abundance data are also available. Using this dataset, we identify significant associations between host genetic variation and microbiome composition in 10 of the 15 body sites tested. These associations are driven by host genetic variation in immunity-related pathways, and are especially enriched in host genes that have been previously associated with microbiome-related complex diseases, such as inflammatory bowel disease and obesity-related disorders. Lastly, we show that host genomic regions associated with the microbiome have high levels of genetic differentiation among human populations, possibly indicating host genomic adaptation to environment-specific microbiomes. Our results highlight the role of host genetic variation in shaping the composition of the human microbiome, and provide a starting point toward understanding the complex interaction between human genetics and the microbiome in the context of human evolution and disease.

Parent–offspring conflicts, “optimal bad motherhood” and the “mother knows best” principles in insect herbivores colonizing novel host plants

PubMed Central

García-Robledo, Carlos; Horvitz, Carol C

2012-01-01

Specialization of insect herbivores to one or a few host plants stimulated the development of two hypotheses on how natural selection should shape oviposition preferences: The “mother knows best” principle suggests that females prefer to oviposit on hosts that increase offspring survival. The “optimal bad motherhood” principle predicts that females prefer to oviposit on hosts that increase their own longevity. In insects colonizing novel host plants, current theory predicts that initial preferences of insect herbivores should be maladaptive, leading to ecological traps. Ecological trap theory does not take into account the fact that insect lineages frequently switch hosts at both ecological and evolutionary time scales. Therefore, the behavior of insect herbivores facing novel hosts is also shaped by natural selection. Using a study system in which four Cephaloleia beetles are currently expanding their diets from native to exotic plants in the order Zingiberales, we determined if initial oviposition preferences are conservative, maladaptive, or follow the patterns predicted by the “mother knows best” or the “optimal bad motherhood” principles. Interactions with novel hosts generated parent–offspring conflicts. Larval survival was higher on native hosts. However, adult generally lived longer on novel hosts. In Cephaloleia beetles, oviposition preferences are usually associated with hosts that increase larval survival, female fecundity, and population growth. In most cases, Cephaloleia oviposition preferences follow the expectations of the “mothers knows best” principle. PMID:22957153

Additive Biotech-Chances, challenges, and recent applications of additive manufacturing technologies in biotechnology.

PubMed

Krujatz, Felix; Lode, Anja; Seidel, Julia; Bley, Thomas; Gelinsky, Michael; Steingroewer, Juliane

2017-10-25

The diversity and complexity of biotechnological applications are constantly increasing, with ever expanding ranges of production hosts, cultivation conditions and measurement tasks. Consequently, many analytical and cultivation systems for biotechnology and bioprocess engineering, such as microfluidic devices or bioreactors, are tailor-made to precisely satisfy the requirements of specific measurements or cultivation tasks. Additive manufacturing (AM) technologies offer the possibility of fabricating tailor-made 3D laboratory equipment directly from CAD designs with previously inaccessible levels of freedom in terms of structural complexity. This review discusses the historical background of these technologies, their most promising current implementations and the associated workflows, fabrication processes and material specifications, together with some of the major challenges associated with using AM in biotechnology/bioprocess engineering. To illustrate the great potential of AM, selected examples in microfluidic devices, 3D-bioprinting/biofabrication and bioprocess engineering are highlighted. Copyright © 2017 Elsevier B.V. All rights reserved.

Macroscale delivery systems for molecular and cellular payloads

NASA Astrophysics Data System (ADS)

Kearney, Cathal J.; Mooney, David J.

2013-11-01

Macroscale drug delivery (MDD) devices are engineered to exert spatiotemporal control over the presentation of a wide range of bioactive agents, including small molecules, proteins and cells. In contrast to systemically delivered drugs, MDD systems act as a depot of drug localized to the treatment site, which can increase drug effectiveness while reducing side effects and confer protection to labile drugs. In this Review, we highlight the key advantages of MDD systems, describe their mechanisms of spatiotemporal control and provide guidelines for the selection of carrier materials. We also discuss the combination of MDD technologies with classic medical devices to create multifunctional MDD devices that improve integration with host tissue, and the use of MDD technology in tissue-engineering strategies to direct cell behaviour. As our ever-expanding knowledge of human biology and disease provides new therapeutic targets that require precise control over their application, the importance of MDD devices in medicine is expected to increase.

Indoor air pollution: Acute adverse health effects and host susceptibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zummo, S.M.; Karol, M.H.

1996-01-01

Increased awareness of the poor quality of indoor air compared with outdoor air has resulted in a significant amount of research on the adverse health effects and mechanisms of action of indoor air pollutants. Common indoor air agents are identified, along with resultant adverse health effects, mechanisms of action, and likely susceptible populations. Indoor air pollutants range from biological agents (such as dust mites) to chemical irritants (such as nitrogen dioxide, carbon monoxide, sulfur dioxide, formaldehyde, and isocyanates). These agents may exert their effects through allergic as well as nonallergic mechanisms. While the public does not generally perceive poor indoormore » air quality as a significant health risk, increasing reports of illness related to indoor air and an expanding base of knowledge on the health effects of indoor air pollution are likely to continue pushing the issue to the forefront.« less

A Novel Extracellular Gut Symbiont in the Marine Worm Priapulus caudatus (Priapulida) Reveals an Alphaproteobacterial Symbiont Clade of the Ecdysozoa.

PubMed

Kroer, Paul; Kjeldsen, Kasper U; Nyengaard, Jens R; Schramm, Andreas; Funch, Peter

2016-01-01

Priapulus caudatus (phylum Priapulida) is a benthic marine predatory worm with a cosmopolitan distribution. In its digestive tract we detected symbiotic bacteria that were consistently present in specimens collected over 8 years from three sites at the Swedish west coast. Based on their 16S rRNA gene sequence, these symbionts comprise a novel genus of the order Rickettsiales (Alphaproteobacteria). Electron microscopy and fluorescence in situ hybridization (FISH) identified them as extracellular, elongate bacteria closely associated with the microvilli, for which we propose the name "Candidatus Tenuibacter priapulorum". Within Rickettsiales, they form a phylogenetically well-defined, family-level clade with uncultured symbionts of marine, terrestrial, and freshwater arthropods. Cand. Tenuibacter priapulorum expands the host range of this candidate family from Arthropoda to the entire Ecdysozoa, which may indicate an evolutionary adaptation of this bacterial group to the microvilli-lined guts of the Ecdysozoa.

A Novel Extracellular Gut Symbiont in the Marine Worm Priapulus caudatus (Priapulida) Reveals an Alphaproteobacterial Symbiont Clade of the Ecdysozoa

PubMed Central

Kroer, Paul; Kjeldsen, Kasper U.; Nyengaard, Jens R.; Schramm, Andreas; Funch, Peter

2016-01-01

Priapulus caudatus (phylum Priapulida) is a benthic marine predatory worm with a cosmopolitan distribution. In its digestive tract we detected symbiotic bacteria that were consistently present in specimens collected over 8 years from three sites at the Swedish west coast. Based on their 16S rRNA gene sequence, these symbionts comprise a novel genus of the order Rickettsiales (Alphaproteobacteria). Electron microscopy and fluorescence in situ hybridization (FISH) identified them as extracellular, elongate bacteria closely associated with the microvilli, for which we propose the name “Candidatus Tenuibacter priapulorum”. Within Rickettsiales, they form a phylogenetically well-defined, family-level clade with uncultured symbionts of marine, terrestrial, and freshwater arthropods. Cand. Tenuibacter priapulorum expands the host range of this candidate family from Arthropoda to the entire Ecdysozoa, which may indicate an evolutionary adaptation of this bacterial group to the microvilli-lined guts of the Ecdysozoa. PMID:27199899

[First report of Echinococcus vogeli in a paca in Misiones province, Argentina].

PubMed

Vizcaychipi, Katherina A; Helou, Marcia; Dematteo, Karen; Macchiaroli, Natalia; Cucher, Marcela; Rosenzvit, Mara; D'Alessandro, Antonio

2013-01-01

We report the first finding of Echinococcus vogeli in a paca, Cuniculus paca, in the tropical forest of Misiones, in the north of Argentina. The presence of the bush dog, Speothos venaticus, E. vogelís only natural definitive host, was also reported. The polycystic hydatids, 2 to 3 cm in diameter, were only found in the liver of an adult paca. The size range of the hooks and the relative proportion blade/handle did not show significant differences with respect to the ones reported for E. vogeli. The size of E. granulosus hooks, measured for comparison purposes, was significantly smaller (p E. vogeli in Argentina. The probability of finding neotropical echinococcosis in humans reinforces the need to expand the search for E. vogeli in Argentina. Echinococcosis due to E. vogeli is very aggressive and may cause death in about a third of the human population affected.

The Expanding Family of Virophages.

PubMed

Bekliz, Meriem; Colson, Philippe; La Scola, Bernard

2016-11-23

Virophages replicate with giant viruses in the same eukaryotic cells. They are a major component of the specific mobilome of mimiviruses. Since their discovery in 2008, five other representatives have been isolated, 18 new genomes have been described, two of which being nearly completely sequenced, and they have been classified in a new viral family, Lavidaviridae . Virophages are small viruses with approximately 35-74 nm large icosahedral capsids and 17-29 kbp large double-stranded DNA genomes with 16-34 genes, among which a very small set is shared with giant viruses. Virophages have been isolated or detected in various locations and in a broad range of habitats worldwide, including the deep ocean and inland. Humans, therefore, could be commonly exposed to virophages, although currently limited evidence exists of their presence in humans based on serology and metagenomics. The distribution of virophages, the consequences of their infection and the interactions with their giant viral hosts within eukaryotic cells deserve further research.

The MVMp P4 promoter is a host cell-type range determinant in vivo.

PubMed

Meir, Chen; Mincberg, Michal; Rostovsky, Irina; Tal, Saar; Vollmers, Ellen M; Levi, Adi; Tattersall, Peter; Davis, Claytus

2017-06-01

The protoparvovirus early promoters, e.g. P4 of Minute Virus of Mice (MVM), play a critical role during infection. Initial P4 activity depends on the host transcription machinery only. Since this is cell-type dependent, it is hypothesized that P4 is a host cell-type range determinant. Yet host range determinants have mapped mostly to capsid, never P4. Here we test the hypothesis using the mouse embryo as a model system. Disruption of the CRE element of P4 drastically decreased infection levels without altering range. However, when we swapped promoter elements of MVM P4 with those from equivalent regions of the closely related H1 virus, we observed elimination of infection in fibroblasts and chondrocytes and the acquisition of infection in skeletal muscle. We conclude that P4 is a host range determinant and a target for modifying the productive infection potential of the virus - an important consideration in adapting these viruses for oncotherapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Genetic diversity in butterflies: Interactive effects of habitat fragmentation and climate-driven range expansion.

PubMed

Hill, Jane K; Hughes, Clare L; Dytham, Calvin; Searle, Jeremy B

2006-03-22

Some species are expanding their ranges polewards during current climate warming. However, anthropogenic fragmentation of suitable habitat is affecting expansion rates and here we investigate interactions between range expansion, habitat fragmentation and genetic diversity. We examined three closely related Satyrinae butterflies, which differ in their habitat associations, from six sites along a transect in England from distribution core to expanding range margin. There was a significant decline in allozyme variation towards an expanding range margin in Pararge aegeria, which has the most restricted habitat availability, but not in Pyronia tithonus whose habitat is more widely available, or in a non-expanding 'control species' (Maniola jurtina). Moreover, data from another transect in Scotland indicated that declines in genetic diversity in P. aegeria were evident only on the transect in England, which had greater habitat fragmentation. Our results indicate that fragmentation of breeding habitats leads to more severe founder events during colonization, resulting in reduced diversity in marginal populations in more specialist species. The continued widespread loss of suitable habitats in the future may increase the likelihood of loss of genetic diversity in expanding species, which may affect whether or not species can adapt to future environmental change.

One Health and Food-Borne Disease: Salmonella Transmission between Humans, Animals, and Plants.

PubMed

Silva, Claudia; Calva, Edmundo; Maloy, Stanley

2014-02-01

There are >2,600 recognized serovars of Salmonella enterica. Many of these Salmonella serovars have a broad host range and can infect a wide variety of animals, including mammals, birds, reptiles, amphibians, fish, and insects. In addition, Salmonella can grow in plants and can survive in protozoa, soil, and water. Hence, broad-host-range Salmonella can be transmitted via feces from wild animals, farm animals, and pets or by consumption of a wide variety of common foods: poultry, beef, pork, eggs, milk, fruit, vegetables, spices, and nuts. Broad-host-range Salmonella pathogens typically cause gastroenteritis in humans. Some Salmonella serovars have a more restricted host range that is associated with changes in the virulence plasmid pSV, accumulation of pseudogenes, and chromosome rearrangements. These changes in host-restricted Salmonella alter pathogen-host interactions such that host-restricted Salmonella organisms commonly cause systemic infections and are transmitted between host populations by asymptomatic carriers. The secondary consequences of efforts to eliminate host-restricted Salmonella serovars demonstrate that basic ecological principles govern the environmental niches occupied by these pathogens, making it impossible to thwart Salmonella infections without a clear understanding of the human, animal, and environmental reservoirs of these pathogens. Thus, transmission of S. enterica provides a compelling example of the One Health paradigm because reducing human infections will require the reduction of Salmonella in animals and limitation of transmission from the environment.

Evolution of Gustatory Receptor Gene Family Provides Insights into Adaptation to Diverse Host Plants in Nymphalid Butterflies.

PubMed

Suzuki, Hiromu C; Ozaki, Katsuhisa; Makino, Takashi; Uchiyama, Hironobu; Yajima, Shunsuke; Kawata, Masakado

2018-06-01

The host plant range of herbivorous insects is a major aspect of insect-plant interaction, but the genetic basis of host range expansion in insects is poorly understood. In butterflies, gustatory receptor genes (GRs) play important roles in host plant selection by ovipositing females. Since several studies have shown associations between the repertoire sizes of chemosensory gene families and the diversity of resource use, we hypothesized that the increase in the number of genes in the GR family is associated with host range expansion in butterflies. Here, we analyzed the evolutionary dynamics of GRs among related species, including the host generalist Vanessa cardui and three specialists. Although the increase of the GR repertoire itself was not observed, we found that the gene birth rate of GRs was the highest in the lineage leading to V. cardui compared with other specialist lineages. We also identified two taxon-specific subfamilies of GRs, characterized by frequent lineage-specific duplications and higher non-synonymous substitution rates. Together, our results suggest that frequent gene duplications in GRs, which might be involved in the detection of plant secondary metabolites, were associated with host range expansion in the V. cardui lineage. These evolutionary patterns imply that the capability to perceive various compounds during host selection was favored during adaptation to diverse host plants.

Consequences of interspecific variation in defenses and herbivore host choice for the ecology and evolution of Inga, a speciose rainforest tree.

PubMed

Coley, Phyllis D; Endara, María-José; Kursar, Thomas A

2018-06-01

We summarize work on a speciose Neotropical tree genus, Inga (Fabaceae), examining how interspecific variation in anti-herbivore defenses may have evolved, how defenses shape host choice by herbivores and how they might regulate community composition and influence species radiations. Defenses of expanding leaves include secondary metabolites, extrafloral nectaries, rapid leaf expansion, trichomes, and synchrony and timing of leaf production. These six classes of defenses are orthogonal, supporting independent evolutionary trajectories. Moreover, only trichomes show a phylogenetic signature, suggesting evolutionary lability in nearly all defenses. The interspecific diversity in secondary metabolite profiles does not arise from the evolution of novel compounds, but from novel combinations of common compounds, presumably due to changes in gene regulation. Herbivore host choice is determined by plant defensive traits, not host phylogeny. Neighboring plants escape each other's pests if their defenses differ enough, thereby enforcing the high local diversity typical of tropical forests. Related herbivores feed on hosts with similar defenses, implying that there are phylogenetic constraints placed on the herbivore traits that are associated with host use. Divergence in defensive traits among Inga appears to be driven by herbivore pressure. However, the lack of congruence between herbivore and host phylogeny suggests that herbivores are tracking defenses, choosing hosts based on traits for which they already have adaptations. There is, therefore, an asymmetry in the host-herbivore evolutionary arms race.

HOST PLANT UTILIZATION, HOST RANGE OSCILLATIONS AND DIVERSIFICATION IN NYMPHALID BUTTERFLIES: A PHYLOGENETIC INVESTIGATION

PubMed Central

Nylin, Sören; Slove, Jessica; Janz, Niklas

2014-01-01

It has been suggested that phenotypic plasticity is a major factor in the diversification of life, and that variation in host range in phytophagous insects is a good model for investigating this claim. We explore the use of angiosperm plants as hosts for nymphalid butterflies, and in particular the evidence for past oscillations in host range and how they are linked to host shifts and to diversification. At the level of orders of plants, a relatively simple pattern of host use and host shifts emerges, despite the 100 million years of history of the family Nymphalidae. We review the evidence that these host shifts and the accompanying diversifications were associated with transient polyphagous stages, as suggested by the “oscillation hypothesis.” In addition, we investigate all currently polyphagous nymphalid species and demonstrate that the state of polyphagy is rare, has a weak phylogenetic signal, and a very apical distribution in the phylogeny; we argue that these are signs of its transient nature. We contrast our results with data from the bark beetles Dendroctonus, in which a more specialized host use is instead the apical state. We conclude that plasticity in host use is likely to have contributed to diversification in nymphalid butterflies. PMID:24372598

Bayesian Diallel Analysis Reveals Mx1-Dependent and Mx1-Independent Effects on Response to Influenza A Virus in Mice.

PubMed

Maurizio, Paul L; Ferris, Martin T; Keele, Gregory R; Miller, Darla R; Shaw, Ginger D; Whitmore, Alan C; West, Ande; Morrison, Clayton R; Noll, Kelsey E; Plante, Kenneth S; Cockrell, Adam S; Threadgill, David W; Pardo-Manuel de Villena, Fernando; Baric, Ralph S; Heise, Mark T; Valdar, William

2018-02-02

Influenza A virus (IAV) is a respiratory pathogen that causes substantial morbidity and mortality during both seasonal and pandemic outbreaks. Infection outcomes in unexposed populations are affected by host genetics, but the host genetic architecture is not well understood. Here, we obtain a broad view of how heritable factors affect a mouse model of response to IAV infection using an 8 × 8 diallel of the eight inbred founder strains of the Collaborative Cross (CC). Expanding on a prior statistical framework for modeling treatment response in diallels, we explore how a range of heritable effects modify acute host response to IAV through 4 d postinfection. Heritable effects in aggregate explained ∼57% of the variance in IAV-induced weight loss. Much of this was attributable to a pattern of additive effects that became more prominent through day 4 postinfection and was consistent with previous reports of antiinfluenza myxovirus resistance 1 ( Mx1 ) polymorphisms segregating between these strains; these additive effects largely recapitulated haplotype effects observed at the Mx1 locus in a previous study of the incipient CC, and are also replicated here in a CC recombinant intercross population. Genetic dominance of protective Mx1 haplotypes was observed to differ by subspecies of origin: relative to the domesticus null Mx1 allele, musculus acts dominantly whereas castaneus acts additively. After controlling for Mx1 , heritable effects, though less distinct, accounted for ∼34% of the phenotypic variance. Implications for future mapping studies are discussed. Copyright © 2018 Maurizio et al.

Investigating the diversity of supernovae type Iax: a MUSE and NOT spectroscopic study of their environments

NASA Astrophysics Data System (ADS)

Lyman, J. D.; Taddia, F.; Stritzinger, M. D.; Galbany, L.; Leloudas, G.; Anderson, J. P.; Eldridge, J. J.; James, P. A.; Krühler, T.; Levan, A. J.; Pignata, G.; Stanway, E. R.

2018-01-01

SN 2002cx-like Type Ia supernovae (also known as SNe Iax) represent one of the most numerous peculiar SN classes. They differ from normal SNe Ia by having fainter peak magnitudes, faster decline rates and lower photospheric velocities, displaying a wide diversity in these properties. We present both integral-field and long-slit visual-wavelength spectroscopy of the host galaxies and explosion sites of SNe Iax to provide constraints on their progenitor formation scenarios. The SN Iax explosion-site metallicity distribution is similar to that of core-collapse SNe and metal poor compared to either normal SNe Ia or SN 1991T-like events. Fainter members, speculated to form distinctly from brighter SN Iax, are found at a range of metallicities, extending to very metal poor environments. Although the SN Iax explosion-sites' ages and star formation rates are comparatively older and less intense than the distribution of star-forming regions across their host galaxies, we confirm the presence of young stellar populations (SPs) at explosion environments for most SNe Iax, expanded here to a larger sample. Ages of the young SPs (several × 107 to 108 yr) are consistent with predictions for young thermonuclear and electron-capture SN progenitors. The lack of extremely young SPs at the explosion sites disfavours very massive progenitors such as Wolf-Rayet explosions with significant fallback. We find weak ionized gas in the only SN Iax host without obvious signs of star formation. The source of the ionization remains ambiguous but appears unlikely to be mainly due to young, massive stars.

Treatment with agonistic DR3 antibody results in expansion of donor Tregs and reduced graft-versus-host disease

PubMed Central

Kim, Byung-Su; Nishikii, Hidekazu; Baker, Jeanette; Pierini, Antonio; Schneidawind, Dominik; Pan, Yuqiong; Beilhack, Andreas; Park, Chung-Gyu

2015-01-01

The paucity of regulatory T cells (Tregs) limits clinical translation to control aberrant immune reactions including graft-versus-host disease (GVHD). Recent studies showed that the agonistic antibody to DR3 (αDR3) expanded CD4+FoxP3+ Tregs in vivo. We investigated whether treating donor mice with a single dose of αDR3 could alleviate acute GVHD in a MHC-mismatched bone marrow transplantation model. αDR3 induced selective proliferation of functional Tregs. CD4+ T cells isolated from αDR3-treated mice contained higher numbers of Tregs and were less proliferative to allogeneic stimuli. In vivo GVHD studies confirmed that Tregs from αDR3-treated donors expanded robustly and higher frequencies of Tregs within donor CD4+ T cells were maintained, resulting in improved survival. Conventional T cells derived from αDR3-treated donors showed reduced activation and proliferation. Serum levels of proinflammatory cytokines (IFNγ, IL-1β, and TNFα) and infiltration of donor T cells into GVHD target tissues (gastrointestinal tract and liver) were decreased. T cells from αDR3-treated donors retained graft-vs-tumor (GVT) effects. In conclusion, a single dose of αDR3 alleviates acute GVHD while preserving GVT effects by selectively expanding and maintaining donor Tregs. This novel strategy will facilitate the clinical application of Treg-based therapies. PMID:26063163

Quantitative computed tomography determined regional lung mechanics in normal nonsmokers, normal smokers and metastatic sarcoma subjects.

PubMed

Choi, Jiwoong; Hoffman, Eric A; Lin, Ching-Long; Milhem, Mohammed M; Tessier, Jean; Newell, John D

2017-01-01

Extra-thoracic tumors send out pilot cells that attach to the pulmonary endothelium. We hypothesized that this could alter regional lung mechanics (tissue stiffening or accumulation of fluid and inflammatory cells) through interactions with host cells. We explored this with serial inspiratory computed tomography (CT) and image matching to assess regional changes in lung expansion. We retrospectively assessed 44 pairs of two serial CT scans on 21 sarcoma patients: 12 without lung metastases and 9 with lung metastases. For each subject, two or more serial inspiratory clinically-derived CT scans were retrospectively collected. Two research-derived control groups were included: 7 normal nonsmokers and 12 asymptomatic smokers with two inspiratory scans taken the same day or one year apart respectively. We performed image registration for local-to-local matching scans to baseline, and derived local expansion and density changes at an acinar scale. Welch two sample t test was used for comparison between groups. Statistical significance was determined with a p value < 0.05. Lung regions of metastatic sarcoma patients (but not the normal control group) demonstrated an increased proportion of normalized lung expansion between the first and second CT. These hyper-expanded regions were associated with, but not limited to, visible metastatic lung lesions. Compared with the normal control group, the percent of increased normalized hyper-expanded lung in sarcoma subjects was significantly increased (p < 0.05). There was also evidence of increased lung "tissue" volume (non-air components) in the hyper-expanded regions of the cancer subjects relative to non-hyper-expanded regions. "Tissue" volume increase was present in the hyper-expanded regions of metastatic and non-metastatic sarcoma subjects. This putatively could represent regional inflammation related to the presence of tumor pilot cell-host related interactions. This new quantitative CT (QCT) method for linking serial acquired inspiratory CT images may provide a diagnostic and prognostic means to objectively characterize regional responses in the lung following oncological treatment and monitoring for lung metastases.

Wind for Schools (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.

2010-05-01

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America's Wind for Schools project addresses these issues by developing Wind Application Centers (WACs) at universities; WAC students assist in implementing school wind turbines and participate in wind courses, by installing small wind turbines at community "host" schools, by implementing teacher training with interactive curricula at each host school. This poster provides an overview of the first two years of the Wind for Schools project, primarily supporting activities in Colorado, Kansas, Nebraska, South Dakota, Montana, andmore » Idaho.« less

Controlling multiple security robots in a warehouse environment

NASA Technical Reports Server (NTRS)

Everett, H. R.; Gilbreath, G. A.; Heath-Pastore, T. A.; Laird, R. T.

1994-01-01

The Naval Command Control and Ocean Surveillance Center (NCCOSC) has developed an architecture to provide coordinated control of multiple autonomous vehicles from a single host console. The multiple robot host architecture (MRHA) is a distributed multiprocessing system that can be expanded to accommodate as many as 32 robots. The initial application will employ eight Cybermotion K2A Navmaster robots configured as remote security platforms in support of the Mobile Detection Assessment and Response System (MDARS) Program. This paper discusses developmental testing of the MRHA in an operational warehouse environment, with two actual and four simulated robotic platforms.

Structural Diversification of Lyngbyatoxin A by Host-Dependent Heterologous Expression of the tleABC Biosynthetic Gene Cluster.

PubMed

Zhang, Lihan; Hoshino, Shotaro; Awakawa, Takayoshi; Wakimoto, Toshiyuki; Abe, Ikuro

2016-08-03

Natural products have enormous structural diversity, yet little is known about how such diversity is achieved in nature. Here we report the structural diversification of a cyanotoxin-lyngbyatoxin A-and its biosynthetic intermediates by heterologous expression of the Streptomyces-derived tleABC biosynthetic gene cluster in three different Streptomyces hosts: S. lividans, S. albus, and S. avermitilis. Notably, the isolated lyngbyatoxin derivatives, including four new natural products, were biosynthesized by crosstalk between the heterologous tleABC gene cluster and the endogenous host enzymes. The simple strategy described here has expanded the structural diversity of lyngbyatoxin A and its biosynthetic intermediates, and provides opportunities for investigation of the currently underestimated hidden biosynthetic crosstalk. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The yeast stands alone: the future of protein biologic production.

PubMed

Love, Kerry R; Dalvie, Neil C; Love, J Christopher

2017-12-22

Yeasts are promising alternative hosts for the manufacturing of recombinant protein therapeutics because they simply and efficiently meet needs for both platform and small-market drugs. Fast accumulation of biomass and low-cost media reduce the cost-of-goods when using yeast, which in turn can enable agile, small-volume manufacturing facilities. Small, tractable yeast genomes are amenable to rapid process development, facilitating strain and product quality by design. Specifically, Pichia pastoris is becoming a widely accepted yeast for biopharmaceutical manufacturing in much of the world owing to a clean secreted product and the rapidly expanding understanding of its cell biology as a host organism. We advocate for a near term partnership spanning industry and academia to promote open source, timely development of yeast hosts. Copyright © 2017. Published by Elsevier Ltd.

Community assembly rules affect the diversity of expanding communities.

PubMed

Peng, Zechen; Zhou, Shurong

2014-11-01

Despite centuries of interest in species range limits, few studies have taken a whole community into consideration. Actually, multiple species may simultaneously respond to environmental changes, for example, global warming, leading a series of dynamical communities toward the advancing front. We investigated multiple species range expansions through the analysis of a two-species dispersion model and simulations of multiple species assemblages regulated by neutral and fecundity-survival trade-offs (FSTs), respectively, and found that species assemblages regulated by different mechanisms would initiate different expanding patterns in geographic ranges in response to environmental changes. The neutral model generally predicts a higher biodiversity near the core of an expanding range, and a lower community similarity compared with a FST model. Without considering the evolution of life history traits, an assortment of the reproduction ability happens at the advancing front under FSTs at the expense of a higher death rate or lower competitive ability. These results emphasize the importance of community assembly rules to the biodiversity maintenance of range expanding communities.

Evolutionary dynamics of host-plant specialization: a case study of the tribe Nymphalini.

PubMed

Janz, N; Nyblom, K; Nylin, S

2001-04-01

Two general patterns that have emerged from the intense studies on insect-host plant associations are a predominance of specialists over generalists and a taxonomic conservatism in host-plant use. In most insect-host plant systems, explanations for these patterns must be based on biases in the processes of host colonizations, host shifts, and specialization, rather than cospeciation. In the present paper, we investigate changes in host range in the nymphalid butterfly tribe Nymphalini, using parsimony optimizations of host-plant data on the butterfly phylogeny. In addition, we performed larval establishment tests to search for larval capacity to feed and survive on plants that have been lost from the female egg-laying repertoire. Optimizations suggested an ancestral association with Urticaceae, and most of the tested species showed a capacity to feed on Urtica dioica regardless of actual host-plant use. In addition, there was a bias among the successful establishments on nonhosts toward plants that are used as hosts by other species in the Nymphalini. An increased likelihood of colonizing ancestral or related plants could also provide an alternative explanation for the observed pattern that some plant families appear to have been colonized independently several times in the tribe. We also show that there is no directionality in host range evolution toward increased specialization, that is, specialization is not a dead end. Instead, changes in host range show a very dynamic pattern.

High-Voltage Aqueous Magnesium Ion Batteries

DOE PAGES

Wang, Fei; Fan, Xiulin; Gao, Tao; ...

2017-10-04

Nonaqueous rechargeable magnesium (Mg) batteries suffer from the complicated and moisture-sensitive electrolyte chemistry. Besides electrolytes, the practicality of a Mg battery is also confined by the absence of high-performance electrode materials due to the intrinsically slow Mg 2+ diffusion in the solids. In this work, we demonstrated a rechargeable aqueous magnesium ion battery (AMIB) concept of high energy density, fast kinetics, and reversibility. Using a superconcentration approach we expanded the electrochemical stability window of the aqueous electrolyte to 2.0 V. More importantly, two new Mg ion host materials, Li superconcentration approach we expanded the electrochemical stability window of the aqueousmore » electrolyte to 2.0 V. More importantly, two new Mg ion host materials, Li 3V 2(PO 4) 3 and poly pyromellitic dianhydride, were developed and employed as cathode and anode electrodes, respectively. Based on comparisons of the aqueous and nonaqueous systems, the role of water is identified to be critical in the Mg ion mobility in the intercalation host but remaining little detrimental to its non-diffusion controlled process. Finally, compared with the previously reported Mg ion cell delivers an unprecedented high power density of 6400 W kg ion cell delivers an unprecedented high power density of 6400 W kg while retaining 92% of the initial capacity after 6000 cycles, pushing the Mg ion cell to a brand new stage.« less

High-Voltage Aqueous Magnesium Ion Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Fei; Fan, Xiulin; Gao, Tao

Nonaqueous rechargeable magnesium (Mg) batteries suffer from the complicated and moisture-sensitive electrolyte chemistry. Besides electrolytes, the practicality of a Mg battery is also confined by the absence of high-performance electrode materials due to the intrinsically slow Mg 2+ diffusion in the solids. In this work, we demonstrated a rechargeable aqueous magnesium ion battery (AMIB) concept of high energy density, fast kinetics, and reversibility. Using a superconcentration approach we expanded the electrochemical stability window of the aqueous electrolyte to 2.0 V. More importantly, two new Mg ion host materials, Li superconcentration approach we expanded the electrochemical stability window of the aqueousmore » electrolyte to 2.0 V. More importantly, two new Mg ion host materials, Li 3V 2(PO 4) 3 and poly pyromellitic dianhydride, were developed and employed as cathode and anode electrodes, respectively. Based on comparisons of the aqueous and nonaqueous systems, the role of water is identified to be critical in the Mg ion mobility in the intercalation host but remaining little detrimental to its non-diffusion controlled process. Finally, compared with the previously reported Mg ion cell delivers an unprecedented high power density of 6400 W kg ion cell delivers an unprecedented high power density of 6400 W kg while retaining 92% of the initial capacity after 6000 cycles, pushing the Mg ion cell to a brand new stage.« less

Obligate Biotrophy Features Unraveled by the Genomic Analysis of the Rust Fungi, Melampsora larici-populina and Puccinia graminis f. sp. tritici

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duplessis, Sebastien; Cuomo, Christina A.; Lin, Yao-Cheng

Rust fungi are some of the most devastating pathogens of crop plants. They are obligate biotrophs, which extract nutrients only from living plant tissues and cannot grow apart from their hosts. Their lifestyle has slowed the dissection of molecular mechanisms underlying host invasion and avoidance or suppression of plant innate immunity. We sequenced the 101 mega base pair genome of Melampsora larici-populina, the causal agent of poplar leaf rust, and the 89 mega base pair genome of Puccinia graminis f. sp. tritici, the causal agent of wheat and barley stem rust. We then compared the 16,841 predicted proteins of M.more » larici-populina to the 18,241 predicted proteins of P. graminis f. sp tritici. Genomic features related to their obligate biotrophic life-style include expanded lineage-specific gene families, a large repertoire of effector-like small secreted proteins (SSPs), impaired nitrogen and sulfur assimilation pathways, and expanded families of amino-acid, oligopeptide and hexose membrane transporters. The dramatic upregulation of transcripts coding for SSPs, secreted hydrolytic enzymes, and transporters in planta suggests that they play a role in host infection and nutrient acquisition. Some of these genomic hallmarks are mirrored in the genomes of other microbial eukaryotes that have independently evolved to infect plants, indicating convergent adaptation to a biotrophic existence inside plant cells« less

Host range and community structure of avian nest parasites in the genus Philornis (Diptera: Muscidae) on the island of Trinidad.

PubMed

Bulgarella, Mariana; Heimpel, George E

2015-09-01

Parasite host range can be influenced by physiological, behavioral, and ecological factors. Combining data sets on host-parasite associations with phylogenetic information of the hosts and the parasites involved can generate evolutionary hypotheses about the selective forces shaping host range. Here, we analyzed associations between the nest-parasitic flies in the genus Philornis and their host birds on Trinidad. Four of ten Philornis species were only reared from one species of bird. Of the parasite species with more than one host bird species, P. falsificus was the least specific and P. deceptivus the most specific attacking only Passeriformes. Philornis flies in Trinidad thus include both specialists and generalists, with varying degrees of specificity within the generalists. We used three quantities to more formally compare the host range of Philornis flies: the number of bird species attacked by each species of Philornis, a phylogenetically informed host specificity index (Poulin and Mouillot's S TD), and a branch length-based S TD. We then assessed the phylogenetic signal of these measures of host range for 29 bird species. None of these measures showed significant phylogenetic signal, suggesting that clades of Philornis did not differ significantly in their ability to exploit hosts. We also calculated two quantities of parasite species load for the birds - the parasite species richness, and a variant of the S TD index based on nodes rather than on taxonomic levels - and assessed the signal of these measures on the bird phylogeny. We did not find significant phylogenetic signal for the parasite species load or the node-based S TD index. Finally, we calculated the parasite associations for all bird pairs using the Jaccard index and regressed these similarity values against the number of nodes in the phylogeny separating bird pairs. This analysis showed that Philornis on Trinidad tend to feed on closely related bird species more often than expected by chance.

Genetic diversity of free-living Symbiodinium in the Caribbean: the importance of habitats and seasons

NASA Astrophysics Data System (ADS)

Granados-Cifuentes, Camila; Neigel, Joseph; Leberg, Paul; Rodriguez-Lanetty, Mauricio

2015-09-01

Although reef corals are dependent of the dinoflagellate Symbiodinium, the large majority of corals spawn gametes that do not contain their vital symbiont. This suggests the existence of a pool of Symbiodinium in the environment, of which surprisingly little is known. Reefs around Curaçao (Caribbean) were sampled for free-living Symbiodinium at three time periods (summer 2009, summer 2010, and winter 2010) to characterize different habitats (water column, coral rubble, sediment, the macroalgae Halimeda spp., Dictyota spp., and Lobophora variegata, and the seagrass Thalassia testudinum) that could serve as environmental sources of symbionts for corals. We detected the common clades of Symbiodinium that engage in symbiosis with Caribbean coral hosts A, B, and C using Symbiodinium-specific primers of the hypervariable region of the chloroplast 23S ribosomal DNA gene. We also discovered clade G and, for the first time in the Caribbean, the presence of free-living Symbiodinium clades F and H. Additionally, this study expands the habitat range of free-living Symbiodinium as environmental Symbiodinium was detected in T. testudinum seagrass beds. The patterns of association between free-living Symbiodinium types and habitats were shown to be complex. An interesting, strong association was seen between some clade A sequence types and sediment, suggesting that sediment could be a niche where clade A radiated from a free-living ancestor. Other interesting relationships were seen between sequence types of Symbiodinium clade C with Halimeda spp. and clades B and F with T. testudinium. These relationships highlight the importance of some macroalgae and seagrasses in hosting free-living Symbiodinium. Finally, studies spanning beyond a 1-yr cycle are needed to further expand on our results in order to better understand the variation of Symbiodinium in the environment through time. All together, results presented here showed that the great diversity of free-living Symbiodinium has a dynamic distribution across habitats and time.

Host range diversification within the IncP-1 plasmid group

PubMed Central

Yano, Hirokazu; Rogers, Linda M.; Knox, Molly G.; Heuer, Holger; Smalla, Kornelia; Brown, Celeste J.

2013-01-01

Broad-host-range plasmids play a critical role in the spread of antibiotic resistance and other traits. In spite of increasing information about the genomic diversity of closely related plasmids, the relationship between sequence divergence and host range remains unclear. IncP-1 plasmids are currently classified into six subgroups based on the genetic distance of backbone genes. We investigated whether plasmids from two subgroups exhibit a different host range, using two IncP-1γ plasmids, an IncP-1β plasmid and their minireplicons. Efficiencies of plasmid establishment and maintenance were compared using five species that belong to the Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria. The IncP-1β plasmid replicated and persisted in all five hosts in the absence of selection. Of the two IncP-1γ plasmids, both were unable to replicate in alphaproteobacterial host Sphingobium japonicum, and one established itself in Agrobacterium tumefaciens but was very unstable. In contrast, both IncP-1γ minireplicons, which produced higher levels of replication initiation protein than the wild-type plasmids, replicated in all strains, suggesting that poor establishment of the native plasmids is in part due to suboptimal replication initiation gene regulation. The findings suggest that host ranges of distinct IncP-1 plasmids only partially overlap, which may limit plasmid recombination and thus result in further genome divergence. PMID:24002747

Canine and feline host ranges of canine parvovirus and feline panleukopenia virus: distinct host cell tropisms of each virus in vitro and in vivo.

PubMed Central

Truyen, U; Parrish, C R

1992-01-01

Canine parvovirus (CPV) emerged as an apparently new virus during the mid-1970s. The origin of CPV is unknown, but a variation from feline panleukopenia virus (FPV) or another closely related parvovirus is suspected. Here we examine the in vitro and in vivo canine and feline host ranges of CPV and FPV. Examination of three canine and six feline cell lines and mitogen-stimulated canine and feline peripheral blood lymphocytes revealed that CPV replicates in both canine and feline cells, whereas FPV replicates efficiently only in feline cells. The in vivo host ranges were unexpectedly complex and distinct from the in vitro host ranges. Inoculation of dogs with FPV revealed efficient replication in the thymus and, to some degree, in the bone marrow, as shown by virus isolation, viral DNA recovery, and Southern blotting and by strand-specific in situ hybridization. FPV replication could not be demonstrated in mesenteric lymph nodes or in the small intestine, which are important target tissues in CPV infection. Although CPV replicated well in all the feline cells tested in vitro, it did not replicate in any tissue of cats after intramuscular or intravenous inoculation. These results indicate that these viruses have complex and overlapping host ranges and that distinct tissue tropisms exist in the homologous and heterologous hosts. Images PMID:1323703

Multispecies Biofilms and Host Responses: “Discriminating the Trees from the Forest”

PubMed Central

Peyyala, R.; Ebersole, J.L.

2014-01-01

Periodontal diseases reflect a tissue destructive process of the hard and soft tissues of the periodontium that are initiated by the accumulation of multispecies bacterial biofilms in the subgingival sulcus. This accumulation, in both quantity and quality of bacteria, results in a chronic immunoinflammatory response of the host to control this noxious challenge, leading to collateral damage of the tissues. As knowledge of the characteristics of the host-bacterial interactions in the oral cavity has expanded, new knowledge has become available on the complexity of the microbial challenge and the repertoire of host responses to this challenge. Recent results from the Human Microbiome Project continue to extend the array of taxa, genera, and species of bacteria that inhabit the multiple niches in the oral cavity; however, there is rather sparse information regarding variations in how host cells discriminate commensal from pathogenic species, as well as how the host response is affected by the 3-dimensional architecture and interbacterial interactions that occur in the oral biofilms. This review provides some insights into thes- processes by including existing literature on the biology of nonoral bacterial biofilms, and the more recent literature just beginning to document how the oral cavity responds to multispecies biofilms. PMID:23141757

Diverse sampling of East African haemosporidians reveals chiropteran origin of malaria parasites in primates and rodents.

PubMed

Lutz, Holly L; Patterson, Bruce D; Kerbis Peterhans, Julian C; Stanley, William T; Webala, Paul W; Gnoske, Thomas P; Hackett, Shannon J; Stanhope, Michael J

2016-06-01

Phylogenies of parasites provide hypotheses on the history of their movements between hosts, leading to important insights regarding the processes of host switching that underlie modern-day epidemics. Haemosporidian (malaria) parasites lack a well resolved phylogeny, which has impeded the study of evolutionary processes associated with host-switching in this group. Here we present a novel phylogenetic hypothesis that suggests bats served as the ancestral hosts of malaria parasites in primates and rodents. Expanding upon current taxon sampling of Afrotropical bat and bird parasites, we find strong support for all major nodes in the haemosporidian tree using both Bayesian and maximum likelihood approaches. Our analyses support a single transition of haemosporidian parasites from saurian to chiropteran hosts, and do not support a monophyletic relationship between Plasmodium parasites of birds and mammals. We find, for the first time, that Hepatocystis and Plasmodium parasites of mammals represent reciprocally monophyletic evolutionary lineages. These results highlight the importance of broad taxonomic sampling when analyzing phylogenetic relationships, and have important implications for our understanding of key host switching events in the history of malaria parasite evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

Has Sarcocystis neurona Dubey et al., 1991 (Sporozoa: Apicomplexa: Sarcocystidae) cospeciated with its intermediate hosts?

PubMed

Elsheikha, Hany M

2009-08-26

The question of how Sarcocystis neurona is able to overcome species barrier and adapt to new hosts is central to the understanding of both the evolutionary origin of S. neurona and the prediction of its field host range. Therefore, it is worth reviewing current knowledge on S. neurona host specificity. The available host range data for S. neurona are discussed in relation to a subject of evolutionary importance-specialist or generalist and its implications to understand the strategies of host adaptation. Current evidences demonstrate that a wide range of hosts exists for S. neurona. This parasite tends to be highly specific for its definitive host but much less so for its intermediate host (I.H.). The unique specificity of S. neurona for its definitive host may be mediated by a probable long coevolutionary relationship of the parasite and carnivores in a restricted ecological niche 'New World'. This might be taken as evidence that carnivores are the 'original' host group for S. neurona. Rather, the capacity of S. neurona to exploit an unusually large number of I.H. species probably indicates that S. neurona maintains non-specificity to its I.H. as an adaptive response to insure the survival of the parasite in areas in which the 'preferred' host is not available. This review concludes with the view that adaptation of S. neurona to a new host is a complex interplay that involves a large number of determinants.

Host tree resistance against the polyphagous

Treesearch

W. D. Morewood; K. Hoover; P. R. Neiner; J.R. McNeil; J. C. Sellmer

2004-01-01

Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae: Lamiini) is an invasive wood-boring beetle with an unusually broad host range and a proven ability to increase its host range as it colonizes new areas and encounters new tree species. The beetle is native to eastern Asia and has become an invasive pest in North America and Europe,...

Hosts of stolbur phytoplasmas in maize redness affected fields

USDA-ARS?s Scientific Manuscript database

The plant host range of a phytoplasma is strongly dependent on the host range of its insect vector. Maize redness in Serbia is caused by stolbur phytoplasma (subgroup 16SrXII-A) and is transmitted by the cixiid planthoper, Reptalus panzeri (Löw). R. panzeri was the only potential vector found to be ...

Eop1 from a Rubus strain of Erwinia amylovora functions as a host-range limiting factor.

PubMed

Asselin, J E; Bonasera, J M; Kim, J F; Oh, C-S; Beer, S V

2011-08-01

Strains of Erwinia amylovora, the bacterium causing the disease fire blight of rosaceous plants, are separated into two groups based on host range: Spiraeoideae and Rubus strains. Spiraeoideae strains have wide host ranges, infecting plants in many rosaceous genera, including apple and pear. In the field, Rubus strains infect the genus Rubus exclusively, which includes raspberry and blackberry. Based on comparisons of limited sequence data from a Rubus and a Spiraeoideae strain, the gene eop1 was identified as unusually divergent, and it was selected as a possible host specificity factor. To test this, eop1 genes from a Rubus strain and a Spiraeoideae strain were cloned and mutated. Expression of the Rubus-strain eop1 reduced the virulence of E. amylovora in immature pear fruit and in apple shoots. Sequencing the orfA-eop1 regions of several strains of E. amylovora confirmed that forms of eop1 are conserved among strains with similar host ranges. This work provides evidence that eop1 from a Rubus-specific strain can function as a determinant of host specificity in E. amylovora.

A model for the energy band gap of GaSbxAs1-x and InSbxAs1-x in the whole composition range

NASA Astrophysics Data System (ADS)

Zhao, Chuan-Zhen; Ren, He-Yu; Wei, Tong; Wang, Sha-Sha; Wang, Jun

2018-04-01

The band gap evolutions of GaSbxAs1-x and InSbxAs1-x in the whole composition range are investigated. It is found that the band gap evolutions of GaSbxAs1-x and InSbxAs1-x are determined by two factors. One is the impurity-host interaction in the As-rich and Sb-rich composition ranges. The other is the intraband coupling within the conduction band and separately within the valence band in the moderate composition range. Based on the band gap evolutions of GaSbxAs1-x and InSbxAs1-x, a model is established. In addition, it is found that the impurity-host interaction is determined by not only the mismatches in size and electronegativity between the introduced atoms in the host material and the anions of the host material, but also the difference in electronegativity between the introduced atoms in the host material and the cations of the host material.

New Hepatitis B Virus of Cranes That Has an Unexpected Broad Host Range

PubMed Central

Prassolov, Alexej; Hohenberg, Heinz; Kalinina, Tatyana; Schneider, Carola; Cova, Lucyna; Krone, Oliver; Frölich, Kai; Will, Hans; Sirma, Hüseyin

2003-01-01

All hepadnaviruses known so far have a very limited host range, restricted to their natural hosts and a few closely related species. This is thought to be due mainly to sequence divergence in the large envelope protein and species-specific differences in host components essential for virus propagation. Here we report an infection of cranes with a novel hepadnavirus, designated CHBV, that has an unexpectedly broad host range and is only distantly evolutionarily related to avihepadnaviruses of related hosts. Direct DNA sequencing of amplified CHBV DNA as well a sequencing of cloned viral genomes revealed that CHBV is most closely related to, although distinct from, Ross' goose hepatitis B virus (RGHBV) and slightly less closely related to duck hepatitis B virus (DHBV). Phylogenetically, cranes are very distant from geese and ducks and are most closely related to herons and storks. Naturally occurring hepadnaviruses in the last two species are highly divergent in sequence from RGHBV and DHBV and do not infect ducks or do so only marginally. In contrast, CHBV from crane sera and recombinant CHBV produced from LMH cells infected primary duck hepatocytes almost as efficiently as DHBV did. This is the first report of a rather broad host range of an avihepadnavirus. Our data imply either usage of similar or identical entry pathways and receptors by DHBV and CHBV, unusual host and virus adaptation mechanisms, or divergent evolution of the host genomes and cellular components required for virus propagation. PMID:12525630

New hepatitis B virus of cranes that has an unexpected broad host range.

PubMed

Prassolov, Alexej; Hohenberg, Heinz; Kalinina, Tatyana; Schneider, Carola; Cova, Lucyna; Krone, Oliver; Frölich, Kai; Will, Hans; Sirma, Hüseyin

2003-02-01

All hepadnaviruses known so far have a very limited host range, restricted to their natural hosts and a few closely related species. This is thought to be due mainly to sequence divergence in the large envelope protein and species-specific differences in host components essential for virus propagation. Here we report an infection of cranes with a novel hepadnavirus, designated CHBV, that has an unexpectedly broad host range and is only distantly evolutionarily related to avihepadnaviruses of related hosts. Direct DNA sequencing of amplified CHBV DNA as well a sequencing of cloned viral genomes revealed that CHBV is most closely related to, although distinct from, Ross' goose hepatitis B virus (RGHBV) and slightly less closely related to duck hepatitis B virus (DHBV). Phylogenetically, cranes are very distant from geese and ducks and are most closely related to herons and storks. Naturally occurring hepadnaviruses in the last two species are highly divergent in sequence from RGHBV and DHBV and do not infect ducks or do so only marginally. In contrast, CHBV from crane sera and recombinant CHBV produced from LMH cells infected primary duck hepatocytes almost as efficiently as DHBV did. This is the first report of a rather broad host range of an avihepadnavirus. Our data imply either usage of similar or identical entry pathways and receptors by DHBV and CHBV, unusual host and virus adaptation mechanisms, or divergent evolution of the host genomes and cellular components required for virus propagation.

Is the nestedness of metazoan parasite assemblages of marine fishes from the southeastern Pacific coast a pattern associated with the geographical distributional range of the host?

PubMed

González, M T; Oliva, M E

2009-04-01

Nested structure is a pattern originally described in island biogeography to characterize how a set of species is distributed among a set of islands. In parasite communities, nestedness has been intensively studied among individual fish from a locality. However, nested patterns among parasite assemblages from different host populations (localities) have scarcely been investigated. We recorded the occurrence of parasites in 9 fish species widely distributed along the southeastern Pacific coast to determine whether the ecto- and endoparasite assemblages of marine fishes show a nested structure associated with host distributional range. Nestedness was tested using Brualdi-Sanderson index of discrepancy (BR); and 5 null models incorporated in a 'Nestedness' programme (Ulrich, 2006). The ecto- and endoparasite richness do not show similar patterns of latitudinal gradients among fish hosts, with 33-66% of analysed ectoparasite assemblages, and 25-75% of endoparasite assemblages showing nested structures through the host distributional range. For ectoparasites, species richness gradients and nested structure (when present) might be associated with decreased host densities or could reflect negative environmental conditions in the distributional border of the host species, whereas for endoparasites might be caused by geographical breaks of prey or changes in prey availability (intermediate hosts). The sampled extension of the distributional range of the host species, as well as the lack of specificity of some parasites, could influence the detection of nestedness.

Association and Host Selectivity in Multi-Host Pathogens

PubMed Central

Malpica, José M.; Sacristán, Soledad; Fraile, Aurora; García-Arenal, Fernando

2006-01-01

The distribution of multi-host pathogens over their host range conditions their population dynamics and structure. Also, host co-infection by different pathogens may have important consequences for the evolution of hosts and pathogens, and host-pathogen co-evolution. Hence it is of interest to know if the distribution of pathogens over their host range is random, or if there are associations between hosts and pathogens, or between pathogens sharing a host. To analyse these issues we propose indices for the observed patterns of host infection by pathogens, and for the observed patterns of co-infection, and tests to analyse if these patterns conform to randomness or reflect associations. Applying these tests to the prevalence of five plant viruses on 21 wild plant species evidenced host-virus associations: most hosts and viruses were selective for viruses and hosts, respectively. Interestingly, the more host-selective viruses were the more prevalent ones, suggesting that host specialisation is a successful strategy for multi-host pathogens. Analyses also showed that viruses tended to associate positively in co-infected hosts. The developed indices and tests provide the tools to analyse how strong and common are these associations among different groups of pathogens, which will help to understand and model the population biology of multi-host pathogens. PMID:17183670

Conflicts and Contestations. Rural Populations' Perspectives on the Second Homes Phenomenon

ERIC Educational Resources Information Center

Rye, Johan Fredrik

2011-01-01

In response to demands to restructure and diversify their economies, many rural communities have welcomed the expanding phenomenon of second homes. However, while the second home owners bring new resources to the host communities, the literature also suggests that large second home populations in rural communities provide fertile ground for a…

The Golden Gate National Parks Phytophthora response plan

Treesearch

Alisa Shor; John Doyle; Sharon Farrell; Alison Forrestel; Christa Conforti; Lew Stringer; Terri Thomas; Laura Lee Sims

2017-01-01

In partnership with the California Native Nursery Network, the three agencies of the Golden Gate National Parks (National Park Service, Golden Gate National Parks Conservancy, and Presidio Trust) hosted the Symposium, “Responding to an Expanding Threat: Exotic Phytophthora Species in Native Plant Nurseries, Restoration Plantings, and Wildlands” in...

VideoANT: Extending Online Video Annotation beyond Content Delivery

ERIC Educational Resources Information Center

Hosack, Bradford

2010-01-01

This paper expands the boundaries of video annotation in education by outlining the need for extended interaction in online video use, identifying the challenges faced by existing video annotation tools, and introducing Video-ANT, a tool designed to create text-based annotations integrated within the time line of a video hosted online. Several…

Cuckoos host range is associated positively with distribution range and negatively with evolutionary uniqueness.

PubMed

Morelli, Federico; Benedetti, Yanina; Møller, Anders Pape; Liang, Wei; Carrascal, Luis M

2018-05-01

The evolutionary distinctiveness (ED) score is a measure of phylogenetic isolation that quantifies the evolutionary uniqueness of a species. Here, we compared the ED score of parasitic and non-parasitic cuckoo species world-wide, to understand whether parental care or parasitism represents the largest amount of phylogenetic uniqueness. Next, we focused only on 46 cuckoo species characterized by brood parasitism with a known number of host species, and we explored the associations among ED score, number of host species and breeding range size for these species. We assessed these associations using phylogenetic generalized least squares (PGLS) models, taking into account the phylogenetic signal. Parasitic cuckoo species were not more unique in terms of ED than non-parasitic species. However, we found a significant negative association between the evolutionary uniqueness and host range and a positive correlation between the number of host species and range size of parasitic cuckoos, probably suggesting a passive sampling of hosts by parasitic species as the breeding range broadens. The findings of this study showed that more generalist brood parasites occupied very different positions in a phylogenetic tree, suggesting that they have evolved independently within the Cuculiformes order. Finally, we demonstrated that specialist cuckoo species also represent the most evolutionarily unique species in the order of Cuculiformes. © 2018 The Authors. Journal of Animal Ecology © 2018 British Ecological Society.

Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus.

PubMed

Wolfe, Benjamin E; Pringle, Anne

2012-04-01

The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world.

Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus

PubMed Central

Wolfe, Benjamin E; Pringle, Anne

2012-01-01

The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world. PMID:22134645

Origins of endothelial and osteogenic cells in the subcutaneous collagen gel implant.

PubMed

Bilic-Curcic, I; Kalajzic, Z; Wang, L; Rowe, D W

2005-11-01

The interdependent relationship between vascular endothelial cells and osteoblasts during bone formation and fracture healing has been long appreciated. This paper reports a heterotopic implant model using FGF-2-expanded bone marrow stromal cells (BMSC) derived from Tie2eGFP (endothelial marker) and pOBCol3.6GFPcyan or topaz (early osteoblast marker) transgenic mice to appreciate the host/donor relationships of cells participating in the process of heterotopic bone formation. The study included various combinations of Tie2eGFP and pOBCol3.6GFPcyan and topaz transgenics as BMSC or whole bone marrow (WBM) donors and also as recipients. Rat tail collagen was used as a carrier of donor cells and implantation was done in lethally irradiated mice rescued with WBM injection. Development of ossicles in the implants was followed weekly during the 4- to 5-week long post-implantation period. By 4-5 weeks after total body irradiation (TBI) and implantation, a well-formed bone spicule had developed that was invested with bone marrow. Experiments showed absolute dominance of donor-derived cells in the formation of endothelial-lined vessels inside the implants as well as the marrow stromal-derived osteogenic cells. Host-derived fibroblasts and osteogenic cells were confined to the fibrous capsule surrounding the implant. In addition, cells lining the endosteal surface of newly formed marrow space carrying a pOBCol3.6GFP marker were observed that were contributed by WBM donor cells and the host. Thus, FGF-2-expanded BMSC appear to be a source of endothelial and osteogenic progenitor cells capable of eliciting heterotopic bone formation independent of cells from the host. This model should be useful for understanding the interactions between these two cell types that control osteogenic differentiation in vivo.

Human-specific bacterial pore-forming toxins induce programmed necrosis in erythrocytes.

PubMed

LaRocca, Timothy J; Stivison, Elizabeth A; Hod, Eldad A; Spitalnik, Steven L; Cowan, Peter J; Randis, Tara M; Ratner, Adam J

2014-08-26

A subgroup of the cholesterol-dependent cytolysin (CDC) family of pore-forming toxins (PFTs) has an unusually narrow host range due to a requirement for binding to human CD59 (hCD59), a glycosylphosphatidylinositol (GPI)-linked complement regulatory molecule. hCD59-specific CDCs are produced by several organisms that inhabit human mucosal surfaces and can act as pathogens, including Gardnerella vaginalis and Streptococcus intermedius. The consequences and potential selective advantages of such PFT host limitation have remained unknown. Here, we demonstrate that, in addition to species restriction, PFT ligation of hCD59 triggers a previously unrecognized pathway for programmed necrosis in primary erythrocytes (red blood cells [RBCs]) from humans and transgenic mice expressing hCD59. Because they lack nuclei and mitochondria, RBCs have typically been thought to possess limited capacity to undergo programmed cell death. RBC programmed necrosis shares key molecular factors with nucleated cell necroptosis, including dependence on Fas/FasL signaling and RIP1 phosphorylation, necrosome assembly, and restriction by caspase-8. Death due to programmed necrosis in RBCs is executed by acid sphingomyelinase-dependent ceramide formation, NADPH oxidase- and iron-dependent reactive oxygen species formation, and glycolytic formation of advanced glycation end products. Bacterial PFTs that are hCD59 independent do not induce RBC programmed necrosis. RBC programmed necrosis is biochemically distinct from eryptosis, the only other known programmed cell death pathway in mature RBCs. Importantly, RBC programmed necrosis enhances the growth of PFT-producing pathogens during exposure to primary RBCs, consistent with a role for such signaling in microbial growth and pathogenesis. In this work, we provide the first description of a new form of programmed cell death in erythrocytes (RBCs) that occurs as a consequence of cellular attack by human-specific bacterial toxins. By defining a new RBC death pathway that shares important components with necroptosis, a programmed necrosis module that occurs in nucleated cells, these findings expand our understanding of RBC biology and RBC-pathogen interactions. In addition, our work provides a link between cholesterol-dependent cytolysin (CDC) host restriction and promotion of bacterial growth in the presence of RBCs, which may provide a selective advantage to human-associated bacterial strains that elaborate such toxins and a potential explanation for the narrowing of host range observed in this toxin family. Copyright © 2014 LaRocca et al.

Expansion of NK cells by engineered K562 cells co-expressing 4-1BBL and mMICA, combined with soluble IL-21.

PubMed

Jiang, Bo; Wu, Xuan; Li, Xi-Ning; Yang, Xi; Zhou, Yulai; Yan, Haowei; Wei, An-Hui; Yan, Weiqun

2014-07-01

NK cells hold promise for protecting hosts from cancer and pathogen infection through direct killing and expressing immune-regulatory cytokines. In our study, a genetically modified K562 cell line with surface expression of 4-1BBL and MICA was constructed to expand functional NK cells in vitro for further adoptive immunotherapy against cancer. After a long-term up to 21 day co-culture with newly isolated peripheral blood mononuclear cells (PBMCs) in the presence of soluble IL-21 (sIL-21), notable increase in proportion of expanded NK cells was observed, especially the CD56(bright)CD16(+) subset. Apparent up-regulation of activating receptors CD38, CD69 and NKG2D was detected on expanded NK cells, so did inhibitory receptor CD94; the cytotoxicity of expanded NK cells against target tumor cells exceeded that of NK cells within fresh PBMCs. The intracellular staining showed expanded NK cells produced immune-regulatory IFN-γ. Taken together, we expanded NK cells with significant up-regulation of activating NKG2D and moderate enhancement of cytotoxicity, with IFN-γ producing ability and a more heterogeneous population of NK cells. These findings provide a novel perspective on expanding NK cells in vitro for further biology study and adoptive immunotherapy of NK cells against cancer. Copyright © 2014 Elsevier Inc. All rights reserved.

Single inclusion piezobarometry confirms high-temperature decompression path for Variscan granulites

NASA Astrophysics Data System (ADS)

Angel, Ross; Alvaro, Matteo; Mazzucchelli, Mattia; Nimis, Paolo; Nestola, Fabrizio

2016-04-01

The identification and chemistry of inclusions trapped in host minerals during growth of the host phase have long been used to infer P-T points on metamorphic paths. The determination of the remnant pressure on the inclusion, e.g., using data from X-ray diffractometry, birefringence analysis or Raman spectroscopy, provides an alternative method of barometry using elasticity theory. A remnant pressure in an inclusion is developed because the inclusion and the host have different thermal expansion and compressibilities, and the inclusion does not expand in response to P and T as would a free crystal. Instead it is restricted to expand only as much as the host mineral, and this constriction in volume can result in inclusions exhibiting over-pressures when the host is studied at room conditions. This concept has been known for a long time, but satisfactory quantitative modelling of inclusion-host systems based on non-linear elasticity theory and precise thermal-pressure euqations of state has only recently come available (Angel et al., 2014, 2015), even though it is still restricted to elastically isotropic minerals. No mineral is elastically isotropic, but garnets and diamond are almost so. Calculations show that diamonds trapped as inclusions in host silicates at P and T within the stability field of diamond should exhibit zero pressure when the samples are recovered to room conditions. However, some diamond inclusions in garnets in granulites are reported to exhibit significant residual overpressures (e.g., Kotková et al., 2011). This indicates that the inclusion was elastically re-equilibrated (e.g., by plastic flow in the garnet host) at high temperatures and lower pressures in the stability field of graphite, consistent also with the observed partial inversion of diamond to graphite. In this case, the elastic analysis of the diamond-in-garnet inclusions provides qualitative independent evidence that the Variscan granulites underwent pressure reduction at high temperatures. The extension of single inclusion piezobarometry to elastically anisotropic minerals will allow quantitative analysis of diamonds trapped in other minerals such as kyanite. This work was supported by ERC starting grant 307322 to Fabrizio Nestola and by the MIUR-SIR grant "MILE DEEp" (RBSI140351) to M. Alvaro. Angel R.J., Mazzucchelli M.L., Alvaro M., Nimis P. & Nestola F. (2014) Geobarometry from host-inclusion systems: the role of elastic relaxation. Am. Mineral., 99, 2146-2149. Angel R.J., Nimis P., Mazzucchelli M.L., Alvaro M. & Nestola F. (2015) How large are departures from lithostatic pressure? Constraints from host-inclusion elasticity. J. Metamorphic Geol., 33, 801-813. Kotková J, O'Brien P.J & Ziemann M.A. (2011)Diamond and coesite discovered in Saxony-type granulite: Solution to the Variscan garnet peridotite enigma. Geology, 39, 667-670.

Diversity and host range of foliar fungal endophytes: are tropical leaves biodiversity hotspots?

PubMed

Arnold, A Elizabeth; Lutzoni, F

2007-03-01

Fungal endophytes are found in asymptomatic photosynthetic tissues of all major lineages of land plants. The ubiquity of these cryptic symbionts is clear, but the scale of their diversity, host range, and geographic distributions are unknown. To explore the putative hyperdiversity of tropical leaf endophytes, we compared endophyte communities along a broad latitudinal gradient from the Canadian arctic to the lowland tropical forest of central Panama. Here, we use molecular sequence data from 1403 endophyte strains to show that endophytes increase in incidence, diversity, and host breadth from arctic to tropical sites. Endophyte communities from higher latitudes are characterized by relatively few species from many different classes of Ascomycota, whereas tropical endophyte assemblages are dominated by a small number of classes with a very large number of endophytic species. The most easily cultivated endophytes from tropical plants have wide host ranges, but communities are dominated by a large number of rare species whose host range is unclear. Even when only the most easily cultured species are considered, leaves of tropical trees represent hotspots of fungal species diversity, containing numerous species not yet recovered from other biomes. The challenge remains to recover and identify those elusive and rarely cultured taxa with narrower host ranges, and to elucidate the ecological roles of these little-known symbionts in tropical forests.

Experience-dependent mushroom body plasticity in butterflies: consequences of search complexity and host range

PubMed Central

Janz, Niklas; Schäpers, Alexander; Gamberale-Stille, Gabriella

2017-01-01

An ovipositing insect experiences many sensory challenges during her search for a suitable host plant. These sensory challenges become exceedingly pronounced when host range increases, as larger varieties of sensory inputs have to be perceived and processed in the brain. Neural capacities can be exceeded upon information overload, inflicting costs on oviposition accuracy. One presumed generalist strategy to diminish information overload is the acquisition of a focused search during its lifetime based on experiences within the current environment, a strategy opposed to a more genetically determined focus expected to be seen in relative specialists. We hypothesized that a broader host range is positively correlated with mushroom body (MB) plasticity, a brain structure related to learning and memory. To test this hypothesis, butterflies with diverging host ranges (Polygonia c-album, Aglais io and Aglais urticae) were subjected to differential environmental complexities for oviposition, after which ontogenetic MB calyx volume differences were compared among species. We found that the relative generalist species exhibited remarkable plasticity in ontogenetic MB volumes; MB growth was differentially stimulated based on the complexity of the experienced environment. For relative specialists, MB volume was more canalized. All in all, this study strongly suggests an impact of host range on brain plasticity in Nymphalid butterflies. PMID:29093221

Effects of host species and population density on Anoplophora glabripennis flight propensity

Treesearch

Joseph A. Francese; David R. Lance; Baode Wang; Zhichun Xu; Alan J. Sawyer; Victor C. Mastro

2007-01-01

Anoplophora glabripennis Motschulsky (Coleoptera: Cerambycidae), the Asian longhorned beetle (ALB) is a pest of hardwoods in its native range of China. While the host range of this pest has been studied extensively, its mechanisms for host selection are still unknown. Our goal was to study the factors influencing movement and orientation of adult ALB...

Host specialization in ticks and transmission of tick-borne diseases: a review

PubMed Central

McCoy, Karen D.; Léger, Elsa; Dietrich, Muriel

2013-01-01

Determining patterns of host use, and the frequency at which these patterns change, are of key importance if we are to understand tick population dynamics, the evolution of tick biodiversity, and the circulation and evolution of associated pathogens. The question of whether ticks are typically host specialists or host generalists has been subject to much debate over the last half-century. Indeed, early research proposed that morphological diversity in ticks was linked to host specific adaptations and that most ticks were specialists. Later work disputed this idea and suggested that ticks are largely limited by biogeographic conditions and tend to use all locally available host species. The work presented in this review suggests that the actual answer likely lies somewhere between these two extremes. Although recent observational studies support the view that phylogenetically diverse host species share ticks when found on similar ecological ranges, theory on host range evolution predicts that host specialization should evolve in ticks given their life history characteristics. Contemporary work employing population genetic tools to examine host-associated population structure in several tick systems support this prediction and show that simple species records are not enough to determine whether a parasite is a true host generalist; host specialization does evolve in ticks at local scales, but may not always lead to speciation. Ticks therefore seem to follow a pattern of being global generalists, local specialists. Given this, the notion of host range needs to be modified from an evolutionary perspective, where one simply counts the number of hosts used across the geographic distribution, to a more ecological view, where one considers host use at a local scale, if we are to better understand the circulation of tick-borne pathogens and exposure risks for humans and livestock. PMID:24109592

Host specialization in ticks and transmission of tick-borne diseases: a review.

PubMed

McCoy, Karen D; Léger, Elsa; Dietrich, Muriel

2013-01-01

Determining patterns of host use, and the frequency at which these patterns change, are of key importance if we are to understand tick population dynamics, the evolution of tick biodiversity, and the circulation and evolution of associated pathogens. The question of whether ticks are typically host specialists or host generalists has been subject to much debate over the last half-century. Indeed, early research proposed that morphological diversity in ticks was linked to host specific adaptations and that most ticks were specialists. Later work disputed this idea and suggested that ticks are largely limited by biogeographic conditions and tend to use all locally available host species. The work presented in this review suggests that the actual answer likely lies somewhere between these two extremes. Although recent observational studies support the view that phylogenetically diverse host species share ticks when found on similar ecological ranges, theory on host range evolution predicts that host specialization should evolve in ticks given their life history characteristics. Contemporary work employing population genetic tools to examine host-associated population structure in several tick systems support this prediction and show that simple species records are not enough to determine whether a parasite is a true host generalist; host specialization does evolve in ticks at local scales, but may not always lead to speciation. Ticks therefore seem to follow a pattern of being global generalists, local specialists. Given this, the notion of host range needs to be modified from an evolutionary perspective, where one simply counts the number of hosts used across the geographic distribution, to a more ecological view, where one considers host use at a local scale, if we are to better understand the circulation of tick-borne pathogens and exposure risks for humans and livestock.

From genes to genomes: a new paradigm for studying fungal pathogenesis in Magnaporthe oryzae.

PubMed

Xu, Jin-Rong; Zhao, Xinhua; Dean, Ralph A

2007-01-01

Magnaporthe oryzae is the most destructive fungal pathogen of rice worldwide and because of its amenability to classical and molecular genetic manipulation, availability of a genome sequence, and other resources it has emerged as a leading model system to study host-pathogen interactions. This chapter reviews recent progress toward elucidation of the molecular basis of infection-related morphogenesis, host penetration, invasive growth, and host-pathogen interactions. Related information on genome analysis and genomic studies of plant infection processes is summarized under specific topics where appropriate. Particular emphasis is placed on the role of MAP kinase and cAMP signal transduction pathways and unique features in the genome such as repetitive sequences and expanded gene families. Emerging developments in functional genome analysis through large-scale insertional mutagenesis and gene expression profiling are detailed. The chapter concludes with new prospects in the area of systems biology, such as protein expression profiling, and highlighting remaining crucial information needed to fully appreciate host-pathogen interactions.

The Giant Resin Bee, Megachile sculpturalis Smith: New Distributional Records for the Mid- and Gulf-south USA

PubMed Central

Tripodi, Amber D.; Sampson, Blair J.

2015-01-01

Abstract Background Megachile (Callomegachile) sculpturalis Smith, the giant resin bee, is an adventive species in the United States. First established in the United States during the early 1990s, records currently exist from most states east of the Mississippi River along with Iowa and Kansas. New information New distributional records are presented for Megachile (Callomegachile) sculpturalis Smith, an introduced bee. Additional records presented here expand the known distribution southwest through Arkansas, Louisiana, Mississippi, Missouri, and Texas. An updated host plant list containing new records is also presented, expanding the number of known floral associations. PMID:26696766

Complete Host Range Testing on Common Reed with Potential Biological Control Agents and Investigation into Biological Control for Flowering Rush

DTIC Science & Technology

2016-07-01

ER D C/ EL C R- 16 -5 Aquatic Plant Control Research Program Complete Host Range Testing on Common Reed with Potential Biological...client/default. Aquatic Plant Control Research Program ERDC/EL CR-16-5 July 2016 Complete Host Range Testing on Common Reed with Potential...and started with sequential no-choice oviposition tests. So far, no eggs were found on any of the 22 test plants offered. The authors also found the

Recurrent evolution of host and vector association in bacteria of the Borrelia burgdorferi sensu lato species complex.

PubMed

Becker, Noémie S; Margos, Gabriele; Blum, Helmut; Krebs, Stefan; Graf, Alexander; Lane, Robert S; Castillo-Ramírez, Santiago; Sing, Andreas; Fingerle, Volker

2016-09-15

The Borrelia burgdorferi sensu lato (s.l.) species complex consists of tick-transmitted bacteria and currently comprises approximately 20 named and proposed genospecies some of which are known to cause Lyme Borreliosis. Species have been defined via genetic distances and ecological niches they occupy. Understanding the evolutionary relationship of species of the complex is fundamental to explaining patterns of speciation. This in turn forms a crucial basis to frame testable hypotheses concerning the underlying processes including host and vector adaptations. Illumina Technology was used to obtain genome-wide sequence data for 93 strains of 14 named genospecies of the B. burgdorferi species complex and genomic data already published for 18 additional strain (including one new species) was added. Phylogenetic reconstruction based on 114 orthologous single copy genes shows that the genospecies represent clearly distinguishable taxa with recent and still ongoing speciation events apparent in Europe and Asia. The position of Borrelia species in the phylogeny is consistent with host associations constituting a major driver for speciation. Interestingly, the data also demonstrate that vector associations are an additional driver for diversification in this tick-borne species complex. This is particularly obvious in B. bavariensis, a rodent adapted species that has diverged from the bird-associated B. garinii most likely in Asia. It now consists of two populations one of which most probably invaded Europe following adaptation to a new vector (Ixodes ricinus) and currently expands its distribution range. The results imply that genotypes/species with novel properties regarding host or vector associations have evolved recurrently during the history of the species complex and may emerge at any time. We suggest that the finding of vector associations as a driver for diversification may be a general pattern for tick-borne pathogens. The core genome analysis presented here provides an important source for investigations of the underlying mechanisms of speciation in tick-borne pathogens.

The Hsp40 proteins of Plasmodium falciparum and other apicomplexa: regulating chaperone power in the parasite and the host.

PubMed

Botha, M; Pesce, E-R; Blatch, G L

2007-01-01

Extensive structural and functional remodelling of Plasmodium falciparum (malaria)-infected erythrocytes follows the export of a range of proteins of parasite origin (exportome) across the parasitophorous vacuole into the host erythrocyte. The genome of P. falciparum encodes a diverse chaperone complement including at least 43 members of the heat shock protein 40kDa (Hsp40) family, and six members of the heat shock protein 70kDa (Hsp70) family. Nearly half of the Hsp40 proteins of P. falciparum are predicted to contain a PEXEL/HT (Plasmodium export element/host targeting signal) sequence motif, and hence are likely to be part of the exportome. In this review we critically evaluate the classification, sequence similarity and clustering, and possible interactors of the P. falciparum Hsp40 chaperone machinery. In addition to the types I, II and III Hsp40 proteins all exhibiting the signature J-domain, the P. falciparum genome also encodes a number of specialized Hsp40 proteins with a J-like domain, which we have categorized as type IV Hsp40 proteins. Analysis of the potential P. falciparum Hsp40 protein interaction network revealed connections predominantly with cytoskeletal and membrane proteins, transcriptional machinery, DNA repair and replication machinery, translational machinery, the proteasome and proteolytic enzymes, and enzymes involved in cellular physiology. Comparison of the Hsp40 proteins of P. falciparum to those of other apicomplexa reveals that most of the proteins (especially the PEXEL/HT-containing proteins) are unique to P. falciparum. Furthermore, very few of the P. falciparum Hsp40 proteins have human homologs, except for those proteins implicated in fundamental biological processes. Our analysis suggests that P. falciparum has evolved an expanded and specialized Hsp40 protein machinery to enable it successfully to invade and remodel the human erythrocyte, and we propose a model in which these proteins are involved in chaperone-mediated translocation, folding, assembly and regulation of parasite and host proteins.

PwRn1, a novel Ty3/gypsy-like retrotransposon of Paragonimus westermani: molecular characters and its differentially preserved mobile potential according to host chromosomal polyploidy.

PubMed

Bae, Young-An; Ahn, Jong-Sook; Kim, Seon-Hee; Rhyu, Mun-Gan; Kong, Yoon; Cho, Seung-Yull

2008-10-14

Retrotransposons have been known to involve in the remodeling and evolution of host genome. These reverse transcribing elements, which show a complex evolutionary pathway with diverse intermediate forms, have been comprehensively analyzed from a wide range of host genomes, while the information remains limited to only a few species in the phylum Platyhelminthes. A LTR retrotransposon and its homologs with a strong phylogenetic affinity toward CsRn1 of Clonorchis sinensis were isolated from a trematode parasite Paragonimus westermani via a degenerate PCR method and from an insect species Anopheles gambiae by in silico analysis of the whole mosquito genome, respectively. These elements, designated PwRn1 and AgCR-1 - AgCR-14 conserved unique features including a t-RNATrp primer binding site and the unusual CHCC signature of Gag proteins. Their flanking LTRs displayed >97% nucleotide identities and thus, these elements were likely to have expanded recently in the trematode and insect genomes. They evolved heterogeneous expression strategies: a single fused ORF, two separate ORFs with an identical reading frame and two ORFs overlapped by -1 frameshifting. Phylogenetic analyses suggested that the elements with the separate ORFs had evolved from an ancestral form(s) with the overlapped ORFs. The mobile potential of PwRn1 was likely to be maintained differentially in association with the karyotype of host genomes, as was examined by the presence/absence of intergenomic polymorphism and mRNA transcripts. Our results on the structural diversity of CsRn1-like elements can provide a molecular tool to dissect a more detailed evolutionary episode of LTR retrotransposons. The PwRn1-associated genomic polymorphism, which is substantial in diploids, will also be informative in addressing genomic diversification following inter-/intra-specific hybridization in P. westermani populations.

Developing a Bacteroides System for Function-Based Screening of DNA from the Human Gut Microbiome.

PubMed

Lam, Kathy N; Martens, Eric C; Charles, Trevor C

2018-01-01

Functional metagenomics is a powerful method that allows the isolation of genes whose role may not have been predicted from DNA sequence. In this approach, first, environmental DNA is cloned to generate metagenomic libraries that are maintained in Escherichia coli, and second, the cloned DNA is screened for activities of interest. Typically, functional screens are carried out using E. coli as a surrogate host, although there likely exist barriers to gene expression, such as lack of recognition of native promoters. Here, we describe efforts to develop Bacteroides thetaiotaomicron as a surrogate host for screening metagenomic DNA from the human gut. We construct a B. thetaiotaomicron-compatible fosmid cloning vector, generate a fosmid clone library using DNA from the human gut, and show successful functional complementation of a B. thetaiotaomicron glycan utilization mutant. Though we were unable to retrieve the physical fosmid after complementation, we used genome sequencing to identify the complementing genes derived from the human gut microbiome. Our results demonstrate that the use of B. thetaiotaomicron to express metagenomic DNA is promising, but they also exemplify the challenges that can be encountered in the development of new surrogate hosts for functional screening. IMPORTANCE Human gut microbiome research has been supported by advances in DNA sequencing that make it possible to obtain gigabases of sequence data from metagenomes but is limited by a lack of knowledge of gene function that leads to incomplete annotation of these data sets. There is a need for the development of methods that can provide experimental data regarding microbial gene function. Functional metagenomics is one such method, but functional screens are often carried out using hosts that may not be able to express the bulk of the environmental DNA being screened. We expand the range of current screening hosts and demonstrate that human gut-derived metagenomic libraries can be introduced into the gut microbe Bacteroides thetaiotaomicron to identify genes based on activity screening. Our results support the continuing development of genetically tractable systems to obtain information about gene function.

Discovery-based studies of schistosome diversity stimulate new hypotheses about parasite biology

PubMed Central

Brant, Sara V.; Loker, Eric S.

2013-01-01

This review provides an update of ongoing efforts to expand our understanding of the diversity inherent within the Schistosomatidae, the parasites responsible for causing schistosomiasis and cercarial dermatitis. By revealing more of the species present, particularly among under-studied avian schistosomes, we gain increased understanding of patterns of schistosome diversification, and their abilities to colonize new hosts and habitats. Schistosomes reveal a surprising ability to switch into new snail and vertebrate host species, into new intra-host habitats, and may adopt novel body forms in the process. Often these changes are not associated with deep splits or long branches in their phylogeny, suggesting they are of relatively recent origin. Several hypotheses prompted by the new observations are discussed, helping to focus thinking on processes influencing not only schistosome diversification, but also their pathogenicity and abundance. PMID:23849836

A few good reasons why species-area relationships do not work for parasites.

PubMed

Strona, Giovanni; Fattorini, Simone

2014-01-01

Several studies failed to find strong relationships between the biological and ecological features of a host and the number of parasite species it harbours. In particular, host body size and geographical range are generally only weak predictors of parasite species richness, especially when host phylogeny and sampling effort are taken into account. These results, however, have been recently challenged by a meta-analytic study that suggested a prominent role of host body size and range extent in determining parasite species richness (species-area relationships). Here we argue that, in general, results from meta-analyses should not discourage researchers from investigating the reasons for the lack of clear patterns, thus proposing a few tentative explanations to the fact that species-area relationships are infrequent or at least difficult to be detected in most host-parasite systems. The peculiar structure of host-parasite networks, the enemy release hypothesis, the possible discrepancy between host and parasite ranges, and the evolutionary tendency of parasites towards specialization may explain why the observed patterns often do not fit those predicted by species-area relationships.

Eilat virus host range restriction is present at multiple levels of the virus life cycle.

PubMed

Nasar, Farooq; Gorchakov, Rodion V; Tesh, Robert B; Weaver, Scott C

2015-01-15

Most alphaviruses are mosquito-borne and exhibit a broad host range, infecting many different vertebrates, including birds, rodents, equids, humans, and nonhuman primates. This ability of most alphaviruses to infect arthropods and vertebrates is essential for their maintenance in nature. Recently, a new alphavirus, Eilat virus (EILV), was described, and in contrast to all other mosquito-borne viruses, it is unable to replicate in vertebrate cell lines. Investigations into the nature of its host range restriction showed the inability of genomic EILV RNA to replicate in vertebrate cells. Here, we investigated whether the EILV host range restriction is present at the entry level and further explored the viral factors responsible for the lack of genomic RNA replication. Utilizing Sindbis virus (SINV) and EILV chimeras, we show that the EILV vertebrate host range restriction is also manifested at the entry level. Furthermore, the EILV RNA replication restriction is independent of the 3' untranslated genome region (UTR). Complementation experiments with SINV suggested that RNA replication is restricted by the inability of the EILV nonstructural proteins to form functional replicative complexes. These data demonstrate that the EILV host range restriction is multigenic, involving at least one gene from both nonstructural protein (nsP) and structural protein (sP) open reading frames (ORFs). As EILV groups phylogenetically within the mosquito-borne virus clade of pathogenic alphaviruses, our findings have important evolutionary implications for arboviruses. Our work explores the nature of host range restriction of the first "mosquito-only alphavirus," EILV. EILV is related to pathogenic mosquito-borne viruses (Eastern equine encephalitis virus [EEEV], Western equine encephalitis virus [WEEV], Venezuelan equine encephalitis virus [VEEV], and Chikungunya virus [CHIKV]) that cause severe disease in humans. Our data demonstrate that EILV is restricted both at entry and genomic RNA replication levels in vertebrate cells. These findings have important implications for arbovirus evolution and will help elucidate the viral factors responsible for the broad host range of pathogenic mosquito-borne alphaviruses, facilitate vaccine development, and inform potential strategies to reduce/prevent alphavirus transmission. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Experimental Adaptation of Burkholderia cenocepacia to Onion Medium Reduces Host Range ▿ † ‡

PubMed Central

Ellis, Crystal N.; Cooper, Vaughn S.

2010-01-01

It is unclear whether adaptation to a new host typically broadens or compromises host range, yet the answer bears on the fate of emergent pathogens and symbionts. We investigated this dynamic using a soil isolate of Burkholderia cenocepacia, a species that normally inhabits the rhizosphere, is related to the onion pathogen B. cepacia, and can infect the lungs of cystic fibrosis patients. We hypothesized that adaptation of B. cenocepacia to a novel host would compromise fitness and virulence in alternative hosts. We modeled adaptation to a specific host by experimentally evolving 12 populations of B. cenocepacia in liquid medium composed of macerated onion tissue for 1,000 generations. The mean fitness of all populations increased by 78% relative to the ancestor, but significant variation among lines was observed. Populations also varied in several phenotypes related to host association, including motility, biofilm formation, and quorum-sensing function. Together, these results suggest that each population adapted by fixing different sets of adaptive mutations. However, this adaptation was consistently accompanied by a loss of pathogenicity to the nematode Caenorhabditis elegans; by 500 generations most populations became unable to kill nematodes. In conclusion, we observed a narrowing of host range as a consequence of prolonged adaptation to an environment simulating a specific host, and we suggest that emergent pathogens may face similar consequences if they become host-restricted. PMID:20154121

The roles of geography and founder effects in promoting host-associated differentiation in the generalist bogus yucca moth Prodoxus decipiens.

PubMed

Darwell, C T; Fox, K A; Althoff, D M

2014-12-01

There is ample evidence that host shifts in plant-feeding insects have been instrumental in generating the enormous diversity of insects. Changes in host use can cause host-associated differentiation (HAD) among populations that may lead to reproductive isolation and eventual speciation. The importance of geography in facilitating this process remains controversial. We examined the geographic context of HAD in the wide-ranging generalist yucca moth Prodoxus decipiens. Previous work demonstrated HAD among sympatric moth populations feeding on two different Yucca species occurring on the barrier islands of North Carolina, USA. We assessed the genetic structure of P. decipiens across its entire geographic and host range to determine whether HAD is widespread in this generalist herbivore. Population genetic analyses of microsatellite and mtDNA sequence data across the entire range showed genetic structuring with respect to host use and geography. In particular, genetic differentiation was relatively strong between mainland populations and those on the barrier islands of North Carolina. Finer scale analyses, however, among sympatric populations using different host plant species only showed significant clustering based on host use for populations on the barrier islands. Mainland populations did not form population clusters based on host plant use. Reduced genetic diversity in the barrier island populations, especially on the derived host, suggests that founder effects may have been instrumental in facilitating HAD. In general, results suggest that the interplay of local adaptation, geography and demography can determine the tempo of HAD. We argue that future studies should include comprehensive surveys across a wide range of environmental and geographic conditions to elucidate the contribution of various processes to HAD. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

The helical screw expander evaluation project. [for geothermal wells

NASA Technical Reports Server (NTRS)

Mckay, R. A.

1977-01-01

A positive-displacement helical-screw expander of the Lysholm type has been adapted for geothermal service and successfully demonstrated in a 50 kW prototype power system. Evaluation of the expander by tests of a new model in a 1 MW power system under wellhead conditions in selected liquid-dominated geothermal fields is proposed. The objectives are to determine the performance characteristics of the expander and power system over a broad range of operating conditions and also to examine the concept of wellhead power plants. Throttling and fractionation of the fluids from the test wells is planned to simulate a wide range of wellhead pressures and steam fractions. Variation in the expander exhaust pressure is also planned. The investigation will include expander efficiency, corrosion, erosion, scale formation and control, and endurance testing. Interaction studies with the wells and an electric grid are also proposed.

Interaction between Flavivirus and Cytoskeleton during Virus Replication

PubMed Central

Foo, Kar Yue; Chee, Hui-Yee

2015-01-01

Flaviviruses are potentially human pathogens that cause major epidemics worldwide. Flavivirus interacts with host cell factors to form a favourable virus replication site. Cell cytoskeletons have been observed to have close contact with flaviviruses, which expands the understanding of cytoskeleton functions during virus replication, although many detailed mechanisms are still unclear. The interactions between the virus and host cytoskeletons such as actin filaments, microtubules, and intermediate filaments have provided insight into molecular alterations during the virus infection, such as viral entry, in-cell transport, scaffold assembly, and egress. This review article focuses on the utilization of cytoskeleton by Flavivirus and the respective functions during virus replication. PMID:26347881

Planned flight test of a mercury ion auxiliary propulsion system. Part 2: Integration with host spacecraft

NASA Technical Reports Server (NTRS)

Knight, R. M.

1978-01-01

The objectives of the flight test and a description on how those objectives are in support of an overall program goal of attaining user application were described. The approach to accomplishment was presented as it applies to integrating the propulsion system with the host spacecraft. A number of known interface design considerations which affect the propulsion system and the spacecraft were discussed. Analogies were drawn comparing the relationship of the organizations involved with this flight test with those anticipated for future operational missions. The paper also expanded upon objectives, system description, mission operations, and measurement of plume effects.

Parasitism genes and host range disparities in biotrophic nematodes: the conundrum of polyphagy versus specialisation.

PubMed

Blok, Vivian C; Jones, John T; Phillips, Mark S; Trudgill, David L

2008-03-01

This essay considers biotrophic cyst and root-knot nematodes in relation to their biology, host-parasite interactions and molecular genetics. These nematodes have to face the biological consequences of the physical constraints imposed by the soil environment in which they live while their hosts inhabit both above and below ground environments. The two groups of nematodes appear to have adopted radically different solutions to these problems with the result that one group is a host specialist and reproduces sexually while the other has an enormous host range and reproduces by mitotic parthenogenesis. We consider what is known about the modes of parasitism used by these nematodes and how it relates to their host range, including the surprising finding that parasitism genes in both nematode groups have been recruited from bacteria. The nuclear and mitochondrial genomes of these two nematode groups are very different and we consider how these findings relate to the biology of the organisms.

Spread of butternut canker in North America, host range, evidence of resistance within butternut populations and conservation genetics

Treesearch

M. E. Ostry; K. Woeste

2004-01-01

Butternut canker is killing trees throughout the range of butternut in North America and is threatening the viability of many populations in several areas. Although butternut is the primary host, other Juglans species and some hardwood species also are potential hosts. Evidence is building that genetic resistance within butternut populations may be...

Molecular and Morphological Analysis Reveals Five New Species of Zygophiala Associated with Flyspeck Signs on Plant Hosts from China

PubMed Central

Gao, Liu; Zhang, Mian; Zhao, Wanyu; Hao, Lu; Chen, Hongcai; Zhang, Rong; Batzer, Jean C.; Gleason, Mark L.; Sun, Guangyu

2014-01-01

Species in the genus Zygophiala are associated with sooty blotch and flyspeck disease on a wide range of hosts. In this study, 63 Zygophiala isolates collected from flyspeck colonies on a range of plants from several regions of China were used for phylogeny, host range and geographic distribution analysis. Phylogenetic trees were constructed on four genes - internal transcribed spacer (ITS), partial translation elongation factor 1-alpha (TEF), β-tubulin (TUB2), and actin (ACT) – both individually and in combination. Isolates were grouped into 11 clades among which five new species, Z. emperorae, Z. trispora, Z. musae, Z. inaequalis and Z. longispora, were described. Species of Zygophiala differed in observed host range and geographic distribution. Z. wisconsinensis and Z. emperorae were the most prevalent throughout the sampled regions of China, whereas Z. trispora, Z. musae, Z. inaequalis and Z. longispora were collected only in southern China. The hosts of Z. wisconsinensis and Z. emperorae were mainly in the family Rosaceae whereas Z. trispora, Z. musae, Z. inaequalis and Z. longispora were found mainly on banana (Musa spp.). Cross inoculation tests provided evidence of host specificity among SBFS species. PMID:25329930

Projecting the Global Distribution of the Emerging Amphibian Fungal Pathogen, Batrachochytrium dendrobatidis, Based on IPCC Climate Futures

PubMed Central

Olson, Deanna H.; Blaustein, Andrew R.

2016-01-01

Projected changes in climate conditions are emerging as significant risk factors to numerous species, affecting habitat conditions and community interactions. Projections suggest species range shifts in response to climate change modifying environmental suitability and is supported by observational evidence. Both pathogens and their hosts can shift ranges with climate change. We consider how climate change may influence the distribution of the emerging infectious amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), a pathogen associated with worldwide amphibian population losses. Using an expanded global Bd database and a novel modeling approach, we examined a broad set of climate metrics to model the Bd-climate niche globally and regionally, then project how climate change may influence Bd distributions. Previous research showed that Bd distribution is dependent on climatic variables, in particular temperature. We trained a machine-learning model (random forest) with the most comprehensive global compilation of Bd sampling records (~5,000 site-level records, mid-2014 summary), including 13 climatic variables. We projected future Bd environmental suitability under IPCC scenarios. The learning model was trained with combined worldwide data (non-region specific) and also separately per region (region-specific). One goal of our study was to estimate of how Bd spatial risks may change under climate change based on the best available data. Our models supported differences in Bd-climate relationships among geographic regions. We projected that Bd ranges will shift into higher latitudes and altitudes due to increased environmental suitability in those regions under predicted climate change. Specifically, our model showed a broad expansion of areas environmentally suitable for establishment of Bd on amphibian hosts in the temperate zones of the Northern Hemisphere. Our projections are useful for the development of monitoring designs in these areas, especially for sensitive species and those vulnerable to multiple threats. PMID:27513565

Global decline in suitable habitat for Angiostrongylus ( = Parastrongylus) cantonensis: the role of climate change.

PubMed

York, Emily M; Butler, Christopher J; Lord, Wayne D

2014-01-01

Climate change is implicated in the alteration of the ranges of species worldwide. Such shifts in species distributions may introduce parasites/pathogens, hosts, and vectors associated with disease to new areas. The parasite Angiostrongylus ( = Parastrongylus) cantonensis is an invasive species that causes eosinophilic meningitis in humans and neurological abnormalities in domestic/wild animals. Although native to southeastern Asia, A. cantonensis has now been reported from more than 30 countries worldwide. Given the health risks, it is important to describe areas with potentially favorable climate for the establishment of A. cantonensis, as well as areas where this pathogen might become established in the future. We used the program Maxent to develop an ecological niche model for A. cantonensis based on 86 localities obtained from published literature. We then modeled areas of potential A. cantonensis distribution as well as areas projected to have suitable climatic conditions under four Representative Concentration Pathways (RCP) scenarios by the 2050s and the 2070s. The best model contained three bioclimatic variables: mean diurnal temperature range, minimum temperature of coldest month and precipitation of warmest quarter. Potentially suitable habitat for A. cantonensis was located worldwide in tropical and subtropical regions. Under all climate change RCP scenarios, the center of the projected distribution shifted away from the equator at a rate of 68-152 km per decade. However, the extent of areas with highly suitable habitat (>50%) declined by 10.66-15.66% by the 2050s and 13.11-16.11% by the 2070s. These results conflict with previous studies, which have generally found that the prevalence of tropical pathogens will increase during the 21st century. Moreover, it is likely that A. cantonensis will continue to expand its current range in the near future due to introductions and host expansion, whereas climate change will reduce the total geographic area of most suitable climatic conditions during the coming decades.

Revisiting Trypanosoma rangeli Transmission Involving Susceptible and Non-Susceptible Hosts

PubMed Central

Ferreira, Luciana de Lima; Pereira, Marcos Horácio; Guarneri, Alessandra Aparecida

2015-01-01

Trypanosoma rangeli infects several triatomine and mammal species in South America. Its transmission is known to occur when a healthy insect feeds on an infected mammal or when an infected insect bites a healthy mammal. In the present study we evaluated the classic way of T. rangeli transmission started by the bite of a single infected triatomine, as well as alternative ways of circulation of this parasite among invertebrate hosts. The number of metacyclic trypomastigotes eliminated from salivary glands during a blood meal was quantified for unfed and recently fed nymphs. The quantification showed that ~50,000 parasites can be liberated during a single blood meal. The transmission of T. rangeli from mice to R. prolixus was evaluated using infections started through the bite of a single infected nymph. The mice that served as the blood source for single infected nymphs showed a high percentage of infection and efficiently transmitted the infection to new insects. Parasites were recovered by xenodiagnosis in insects fed on mice with infections that lasted approximately four months. Hemolymphagy and co-feeding were tested to evaluate insect-insect T. rangeli transmission. T. rangeli was not transmitted during hemolymphagy. However, insects that had co-fed on mice with infected conspecifics exhibited infection rates of approximately 80%. Surprisingly, 16% of the recipient nymphs became infected when pigeons were used as hosts. Our results show that T. rangeli is efficiently transmitted between the evaluated hosts. Not only are the insect-mouse-insect transmission rates high, but parasites can also be transmitted between insects while co-feeding on a living host. We show for the first time that birds can be part of the T. rangeli transmission cycle as we proved that insect-insect transmission is feasible during a co-feeding on these hosts. PMID:26469403

Extremely thermophilic microorganisms as metabolic engineering platforms for production of fuels and industrial chemicals.

PubMed

Zeldes, Benjamin M; Keller, Matthew W; Loder, Andrew J; Straub, Christopher T; Adams, Michael W W; Kelly, Robert M

2015-01-01

Enzymes from extremely thermophilic microorganisms have been of technological interest for some time because of their ability to catalyze reactions of industrial significance at elevated temperatures. Thermophilic enzymes are now routinely produced in recombinant mesophilic hosts for use as discrete biocatalysts. Genome and metagenome sequence data for extreme thermophiles provide useful information for putative biocatalysts for a wide range of biotransformations, albeit involving at most a few enzymatic steps. However, in the past several years, unprecedented progress has been made in establishing molecular genetics tools for extreme thermophiles to the point that the use of these microorganisms as metabolic engineering platforms has become possible. While in its early days, complex metabolic pathways have been altered or engineered into recombinant extreme thermophiles, such that the production of fuels and chemicals at elevated temperatures has become possible. Not only does this expand the thermal range for industrial biotechnology, it also potentially provides biodiverse options for specific biotransformations unique to these microorganisms. The list of extreme thermophiles growing optimally between 70 and 100°C with genetic toolkits currently available includes archaea and bacteria, aerobes and anaerobes, coming from genera such as Caldicellulosiruptor, Sulfolobus, Thermotoga, Thermococcus, and Pyrococcus. These organisms exhibit unusual and potentially useful native metabolic capabilities, including cellulose degradation, metal solubilization, and RuBisCO-free carbon fixation. Those looking to design a thermal bioprocess now have a host of potential candidates to choose from, each with its own advantages and challenges that will influence its appropriateness for specific applications. Here, the issues and opportunities for extremely thermophilic metabolic engineering platforms are considered with an eye toward potential technological advantages for high temperature industrial biotechnology.

Extremely thermophilic microorganisms as metabolic engineering platforms for production of fuels and industrial chemicals

PubMed Central

Zeldes, Benjamin M.; Keller, Matthew W.; Loder, Andrew J.; Straub, Christopher T.; Adams, Michael W. W.; Kelly, Robert M.

2015-01-01

Enzymes from extremely thermophilic microorganisms have been of technological interest for some time because of their ability to catalyze reactions of industrial significance at elevated temperatures. Thermophilic enzymes are now routinely produced in recombinant mesophilic hosts for use as discrete biocatalysts. Genome and metagenome sequence data for extreme thermophiles provide useful information for putative biocatalysts for a wide range of biotransformations, albeit involving at most a few enzymatic steps. However, in the past several years, unprecedented progress has been made in establishing molecular genetics tools for extreme thermophiles to the point that the use of these microorganisms as metabolic engineering platforms has become possible. While in its early days, complex metabolic pathways have been altered or engineered into recombinant extreme thermophiles, such that the production of fuels and chemicals at elevated temperatures has become possible. Not only does this expand the thermal range for industrial biotechnology, it also potentially provides biodiverse options for specific biotransformations unique to these microorganisms. The list of extreme thermophiles growing optimally between 70 and 100°C with genetic toolkits currently available includes archaea and bacteria, aerobes and anaerobes, coming from genera such as Caldicellulosiruptor, Sulfolobus, Thermotoga, Thermococcus, and Pyrococcus. These organisms exhibit unusual and potentially useful native metabolic capabilities, including cellulose degradation, metal solubilization, and RuBisCO-free carbon fixation. Those looking to design a thermal bioprocess now have a host of potential candidates to choose from, each with its own advantages and challenges that will influence its appropriateness for specific applications. Here, the issues and opportunities for extremely thermophilic metabolic engineering platforms are considered with an eye toward potential technological advantages for high temperature industrial biotechnology. PMID:26594201

Impact of Vector Dispersal and Host-Plant Fidelity on the Dissemination of an Emerging Plant Pathogen

PubMed Central

Johannesen, Jes; Foissac, Xavier; Kehrli, Patrik; Maixner, Michael

2012-01-01

Dissemination of vector-transmitted pathogens depend on the survival and dispersal of the vector and the vector's ability to transmit the pathogen, while the host range of vector and pathogen determine the breath of transmission possibilities. In this study, we address how the interaction between dispersal and plant fidelities of a pathogen (stolbur phytoplasma tuf-a) and its vector (Hyalesthes obsoletus: Cixiidae) affect the emergence of the pathogen. Using genetic markers, we analysed the geographic origin and range expansion of both organisms in Western Europe and, specifically, whether the pathogen's dissemination in the northern range is caused by resident vectors widening their host-plant use from field bindweed to stinging nettle, and subsequent host specialisation. We found evidence for common origins of pathogen and vector south of the European Alps. Genetic patterns in vector populations show signals of secondary range expansion in Western Europe leading to dissemination of tuf-a pathogens, which might be newly acquired and of hybrid origin. Hence, the emergence of stolbur tuf-a in the northern range was explained by secondary immigration of vectors carrying stinging nettle-specialised tuf-a, not by widening the host-plant spectrum of resident vectors with pathogen transmission from field bindweed to stinging nettle nor by primary co-migration from the resident vector's historical area of origin. The introduction of tuf-a to stinging nettle in the northern range was therefore independent of vector's host-plant specialisation but the rapid pathogen dissemination depended on the vector's host shift, whereas the general dissemination elsewhere was linked to plant specialisation of the pathogen but not of the vector. PMID:23284774

Impact of vector dispersal and host-plant fidelity on the dissemination of an emerging plant pathogen.

PubMed

Johannesen, Jes; Foissac, Xavier; Kehrli, Patrik; Maixner, Michael

2012-01-01

Dissemination of vector-transmitted pathogens depend on the survival and dispersal of the vector and the vector's ability to transmit the pathogen, while the host range of vector and pathogen determine the breath of transmission possibilities. In this study, we address how the interaction between dispersal and plant fidelities of a pathogen (stolbur phytoplasma tuf-a) and its vector (Hyalesthes obsoletus: Cixiidae) affect the emergence of the pathogen. Using genetic markers, we analysed the geographic origin and range expansion of both organisms in Western Europe and, specifically, whether the pathogen's dissemination in the northern range is caused by resident vectors widening their host-plant use from field bindweed to stinging nettle, and subsequent host specialisation. We found evidence for common origins of pathogen and vector south of the European Alps. Genetic patterns in vector populations show signals of secondary range expansion in Western Europe leading to dissemination of tuf-a pathogens, which might be newly acquired and of hybrid origin. Hence, the emergence of stolbur tuf-a in the northern range was explained by secondary immigration of vectors carrying stinging nettle-specialised tuf-a, not by widening the host-plant spectrum of resident vectors with pathogen transmission from field bindweed to stinging nettle nor by primary co-migration from the resident vector's historical area of origin. The introduction of tuf-a to stinging nettle in the northern range was therefore independent of vector's host-plant specialisation but the rapid pathogen dissemination depended on the vector's host shift, whereas the general dissemination elsewhere was linked to plant specialisation of the pathogen but not of the vector.

The ecology, evolution, impacts and management of host-parasite interactions of marine molluscs.

PubMed

Coen, Loren D; Bishop, Melanie J

2015-10-01

Molluscs are economically and ecologically important components of aquatic ecosystems. In addition to supporting valuable aquaculture and wild-harvest industries, their populations determine the structure of benthic communities, cycling of nutrients, serve as prey resources for higher trophic levels and, in some instances, stabilize shorelines and maintain water quality. This paper reviews existing knowledge of the ecology of host-parasite interactions involving marine molluscs, with a focus on gastropods and bivalves. It considers the ecological and evolutionary impacts of molluscan parasites on their hosts and vice versa, and on the communities and ecosystems in which they are a part, as well as disease management and its ecological impacts. An increasing number of case studies show that disease can have important effects on marine molluscs, their ecological interactions and ecosystem services, at spatial scales from centimeters to thousands of kilometers and timescales ranging from hours to years. In some instances the cascading indirect effects arising from parasitic infection of molluscs extend well beyond the temporal and spatial scales at which molluscs are affected by disease. In addition to the direct effects of molluscan disease, there can be large indirect impacts on marine environments resulting from strategies, such as introduction of non-native species and selective breeding for disease resistance, put in place to manage disease. Much of our understanding of impacts of molluscan diseases on the marine environment has been derived from just a handful of intensively studied marine parasite-host systems, namely gastropod-trematode, cockle-trematode, and oyster-protistan interactions. Understanding molluscan host-parasite dynamics is of growing importance because: (1) expanding aquaculture; (2) current and future climate change; (3) movement of non-native species; and (4) coastal development are modifying molluscan disease dynamics, ultimately leading to complex relationships between diseases and cultivated and natural molluscan populations. Further, in some instances the enhancement or restoration of valued ecosystem services may be contingent on management of molluscan disease. The application of newly emerging molecular tools and remote sensing techniques to the study of molluscan disease will be important in identifying how changes at varying spatial and temporal scales with global change are modifying host-parasite systems. Copyright © 2015 Elsevier Inc. All rights reserved.

Influenza A Virus Polymerase Is a Site for Adaptive Changes during Experimental Evolution in Bat Cells

PubMed Central

Poole, Daniel S.; Yú, Shuǐqìng; Caì, Yíngyún; Dinis, Jorge M.; Müller, Marcel A.; Jordan, Ingo; Friedrich, Thomas C.; Kuhn, Jens H.

2014-01-01

ABSTRACT The recent identification of highly divergent influenza A viruses in bats revealed a new, geographically dispersed viral reservoir. To investigate the molecular mechanisms of host-restricted viral tropism and the potential for transmission of viruses between humans and bats, we exposed a panel of cell lines from bats of diverse species to a prototypical human-origin influenza A virus. All of the tested bat cell lines were susceptible to influenza A virus infection. Experimental evolution of human and avian-like viruses in bat cells resulted in efficient replication and created highly cytopathic variants. Deep sequencing of adapted human influenza A virus revealed a mutation in the PA polymerase subunit not previously described, M285K. Recombinant virus with the PA M285K mutation completely phenocopied the adapted virus. Adaptation of an avian virus-like virus resulted in the canonical PB2 E627K mutation that is required for efficient replication in other mammals. None of the adaptive mutations occurred in the gene for viral hemagglutinin, a gene that frequently acquires changes to recognize host-specific variations in sialic acid receptors. We showed that human influenza A virus uses canonical sialic acid receptors to infect bat cells, even though bat influenza A viruses do not appear to use these receptors for virus entry. Our results demonstrate that bats are unique hosts that select for both a novel mutation and a well-known adaptive mutation in the viral polymerase to support replication. IMPORTANCE Bats constitute well-known reservoirs for viruses that may be transferred into human populations, sometimes with fatal consequences. Influenza A viruses have recently been identified in bats, dramatically expanding the known host range of this virus. Here we investigated the replication of human influenza A virus in bat cell lines and the barriers that the virus faces in this new host. Human influenza A and B viruses infected cells from geographically and evolutionarily diverse New and Old World bats. Viruses mutated during infections in bat cells, resulting in increased replication and cytopathic effects. These mutations were mapped to the viral polymerase and shown to be solely responsible for adaptation to bat cells. Our data suggest that replication of human influenza A viruses in a nonnative host drives the evolution of new variants and may be an important source of genetic diversity. PMID:25142579

Random yet deterministic: convergent immunoglobulin responses to influenza.

PubMed

Martins, Andrew J; Tsang, John S

2014-09-01

B cell clonal expansion is a hallmark of host-defense and vaccination responses. Given the vast immunoglobulin repertoire, individuals may expand B cells carrying largely distinct immunoglobulin genes following antigenic challenge. Using immunoglobulin-repertoire sequencing to dynamically track responses to influenza vaccination, Jackson et al. find evidence of convergent immunoglobulin responses across individuals. Published by Elsevier Ltd.

The Written Text and Human Dialogue: Pedagogical Responses to the Age of Hypertext Media.

ERIC Educational Resources Information Center

Ehrhart, Donna J.; Boyd, Charley

In June 1995, New York's Genesee Community College hosted "The Written Text and Human Dialogue," a 4-week faculty development seminar for 30 professors in the humanities and technical disciplines across the United States. The seminar sought to explore the history of human communication and writing, to expand participants' knowledge of writing…

Recreation Use of the Ocala National Forest in Florida

Treesearch

George A. James; Robert A. Harper

1965-01-01

Forest land managers charged with operating and developing an outdoor recreation complex--whether large or small, public or private - constantly face a host of management decisions. What are my cleanup and maintenance needs? What uses and facilities should be provided? Should I expand? Should I add new units? These questions are not easy to answer. And before sound...

A need to define characteristics to be used in the taxonomy of the expanding pestivirus genus

USDA-ARS?s Scientific Manuscript database

The relatively high rate of genetic drift observed with pestiviruses results not only in the emergence of new species but also in heterogeneity within recognized species. The grouping of pestiviruses into species was first based on host and to a lesser extent clinical presentation, then later by an...

NOAA & Academia Partnership Building Conference. Highlights (3rd, Washington, DC, November 14-15, 2001).

ERIC Educational Resources Information Center

National Oceanic and Atmospheric Administration (DOC), Silver Spring, MD.

In November 2001 the National Oceanic and Atmospheric Administration (NOAA) hosted the third NOAA and Academia Partnership to evaluate, maintain, and expand on efforts to optimize NOAA-university cooperation. Close partnership between the NOAA and U.S. universities has produced many benefits for the U.S. economy and the environment. Based on the…

Social Skills Difficulty: Model of Culture Shock for International Graduate Students

ERIC Educational Resources Information Center

Chapdelaine, Raquel Faria; Alexitch, Louise R.

2004-01-01

This study expanded and tested Furnham and Bochner's (1982) model of culture shock, employing a sample of 156 male international students in a Canadian university. Path analysis was used to assess the effects of cultural differences, size of co-national group, family status, cross-cultural experience, and social interaction with hosts on culture…

Host compatibility rather than vector–host-encounter rate determines the host range of avian Plasmodium parasites

PubMed Central

Medeiros, Matthew C. I.; Hamer, Gabriel L.; Ricklefs, Robert E.

2013-01-01

Blood-feeding arthropod vectors are responsible for transmitting many parasites between vertebrate hosts. While arthropod vectors often feed on limited subsets of potential host species, little is known about the extent to which this influences the distribution of vector-borne parasites in some systems. Here, we test the hypothesis that different vector species structure parasite–host relationships by restricting access of certain parasites to a subset of available hosts. Specifically, we investigate how the feeding patterns of Culex mosquito vectors relate to distributions of avian malaria parasites among hosts in suburban Chicago, IL, USA. We show that Plasmodium lineages, defined by cytochrome b haplotypes, are heterogeneously distributed across avian hosts. However, the feeding patterns of the dominant vectors (Culex restuans and Culex pipiens) are similar across these hosts, and do not explain the distributions of Plasmodium parasites. Phylogenetic similarity of avian hosts predicts similarity in their Plasmodium parasites. This effect was driven primarily by the general association of Plasmodium parasites with particular host superfamilies. Our results suggest that a mosquito-imposed encounter rate does not limit the distribution of avian Plasmodium parasites across hosts. This implies that compatibility between parasites and their avian hosts structure Plasmodium host range. PMID:23595266

Comparison of field-collected ascovirus isolates by DNA hybridization, host range, and histopathology.

PubMed

Hamm, J J; Styer, E L; Federici, B A

1998-09-01

Six field-collected ascovirus isolates obtained from five noctuid species in the continental United States were compared with respect to the general relatedness of their DNA, host range, and histopathology. Two isolates were from Spodoptera frugiperda, and the other four were from Autographa precationis, Heliothis virescens, Helicoverpa zea, and Trichoplusia ni. DNA-DNA hybridization studies showed that the six isolates belonged to three distinct viral species, with the isolates from S. frugiperda composing one species, those from A. precationis and H. virescens a second species, and those from H. zea and T. ni a third species. The host range and histopathology of each isolate was studied in eight noctuid species, S. frugiperda, Spodoptera ornithogalli, Spodoptera exigua, Spodoptera eridania, H. virescens, H. zea, A. precationis, and Feltia subterranea. Though some variation existed between the different isolates of each viral species, distinct patterns were apparent for each. The viral species from S. frugiperda had a host range that was limited primarily to Spodoptera species and both isolates of this virus only replicated and caused significant pathology in the fat body, whereas the viral species from A. precationis and H. virescens had a much broader host range that included most of the species tested, but also had a tissue tropism primarily restricted to the fat body. The viral species from T. ni and H. zea readily infected all the hosts tested, where the principal site of replication and significant pathology was the epidermis. In many test hosts, however, this viral species also replicated and caused significant pathology in the tracheal epithelium and to a lesser extent in the fat body. Aside from contributing to knowledge of ascovirus biology, these studies indicate that DNA hybridization profiles combined with studies of host range and tissue tropism can be used as characters for defining ascovirus species. Copyright 1998 Academic Press.

Climate change and infectious diseases in the Arctic: establishment of a circumpolar working group

PubMed Central

Parkinson, Alan J.; Evengard, Birgitta; Semenza, Jan C.; Ogden, Nicholas; Børresen, Malene L.; Berner, Jim; Brubaker, Michael; Sjöstedt, Anders; Evander, Magnus; Hondula, David M.; Menne, Bettina; Pshenichnaya, Natalia; Gounder, Prabhu; Larose, Tricia; Revich, Boris; Hueffer, Karsten; Albihn, Ann

2014-01-01

The Arctic, even more so than other parts of the world, has warmed substantially over the past few decades. Temperature and humidity influence the rate of development, survival and reproduction of pathogens and thus the incidence and prevalence of many infectious diseases. Higher temperatures may also allow infected host species to survive winters in larger numbers, increase the population size and expand their habitat range. The impact of these changes on human disease in the Arctic has not been fully evaluated. There is concern that climate change may shift the geographic and temporal distribution of a range of infectious diseases. Many infectious diseases are climate sensitive, where their emergence in a region is dependent on climate-related ecological changes. Most are zoonotic diseases, and can be spread between humans and animals by arthropod vectors, water, soil, wild or domestic animals. Potentially climate-sensitive zoonotic pathogens of circumpolar concern include Brucella spp., Toxoplasma gondii, Trichinella spp., Clostridium botulinum, Francisella tularensis, Borrelia burgdorferi, Bacillus anthracis, Echinococcus spp., Leptospira spp., Giardia spp., Cryptosporida spp., Coxiella burnetti, rabies virus, West Nile virus, Hantaviruses, and tick-borne encephalitis viruses. PMID:25317383

Detection and Characterization of Homologues of Human Hepatitis Viruses and Pegiviruses in Rodents and Bats in Vietnam.

PubMed

Van Nguyen, Dung; Van Nguyen, Cuong; Bonsall, David; Ngo, Tue Tri; Carrique-Mas, Juan; Pham, Anh Hong; Bryant, Juliet E; Thwaites, Guy; Baker, Stephen; Woolhouse, Mark; Simmonds, Peter

2018-02-28

Rodents and bats are now widely recognised as important sources of zoonotic virus infections in other mammals, including humans. Numerous surveys have expanded our knowledge of diverse viruses in a range of rodent and bat species, including their origins, evolution, and range of hosts. In this study of pegivirus and human hepatitis-related viruses, liver and serum samples from Vietnamese rodents and bats were examined by PCR and sequencing. Nucleic acids homologous to human hepatitis B, C, E viruses were detected in liver samples of 2 (1.3%) of 157 bats, 38 (8.1%), and 14 (3%) of 470 rodents, respectively. Hepacivirus-like viruses were frequently detected (42.7%) in the bamboo rat, Rhizomys pruinosus , while pegivirus RNA was only evident in 2 (0.3%) of 638 rodent serum samples. Complete or near-complete genome sequences of HBV, HEV and pegivirus homologues closely resembled those previously reported from rodents and bats. However, complete coding region sequences of the rodent hepacivirus-like viruses substantially diverged from all of the currently classified variants and potentially represent a new species in the Hepacivirus genus. Of the viruses identified, their routes of transmission and potential to establish zoonoses remain to be determined.

Molecular Detection of Theileria spp. in Livestock on Five Caribbean Islands.

PubMed

Zhang, Jilei; Kelly, Patrick; Li, Jing; Xu, Chuanling; Wang, Chengming

2015-01-01

Theileria spp. are tick-transmitted, intracellular apicomplexan protozoan parasites infecting a wide range of animals. As there is very limited information on the prevalence of Theileria spp. in the Caribbean we used the recently described genus-specific pan-Theileria FRET-qPCR to identify infected animals in the region and a standard 18S rRNA gene PCR and sequencing to determine the species involved. We found Theileria spp. in 9% of the convenience samples of animals (n = 752) studied from five Caribbean islands. Donkeys (20.0%: 5/25) were most commonly infected, followed by sheep (17.4%, 25/144), cattle (6.8%; 22/325), goats (5.0%; 12/238), and horses (5.0%; 1/20). Six species of Theileria were identified: T. equi (donkeys, cattle, goats, and sheep), Theileria sp. OT3 (sheep and goats), Theileria sp. NG-2013a (cattle), Theileria sp. YW-2014 (donkeys), Theileria sp. B15a (goats), and Babesia vulpes or a closely related organism (sheep and goats). Only T. equi has been previously reported in the Caribbean. Our findings expand the known host ranges of Theileria spp. and the known distribution of the organisms around the world.

Molecular Detection of Theileria spp. in Livestock on Five Caribbean Islands

PubMed Central

2015-01-01

Theileria spp. are tick-transmitted, intracellular apicomplexan protozoan parasites infecting a wide range of animals. As there is very limited information on the prevalence of Theileria spp. in the Caribbean we used the recently described genus-specific pan-Theileria FRET-qPCR to identify infected animals in the region and a standard 18S rRNA gene PCR and sequencing to determine the species involved. We found Theileria spp. in 9% of the convenience samples of animals (n = 752) studied from five Caribbean islands. Donkeys (20.0%: 5/25) were most commonly infected, followed by sheep (17.4%, 25/144), cattle (6.8%; 22/325), goats (5.0%; 12/238), and horses (5.0%; 1/20). Six species of Theileria were identified: T. equi (donkeys, cattle, goats, and sheep), Theileria sp. OT3 (sheep and goats), Theileria sp. NG-2013a (cattle), Theileria sp. YW-2014 (donkeys), Theileria sp. B15a (goats), and Babesia vulpes or a closely related organism (sheep and goats). Only T. equi has been previously reported in the Caribbean. Our findings expand the known host ranges of Theileria spp. and the known distribution of the organisms around the world. PMID:26783522

Anterograde or Retrograde Transsynaptic Circuit Tracing in Vertebrates with Vesicular Stomatitis Virus Vectors

PubMed Central

Beier, Kevin T.; Mundell, Nathan A.; Pan, Y. Albert; Cepko, Constance L.

2016-01-01

Viruses have been used as transsynaptic tracers, allowing one to map the inputs and outputs of neuronal populations, due to their ability to replicate in neurons and transmit in vivo only across synaptically connected cells. To date, their use has been largely restricted to mammals. In order to explore the use of such viruses in an expanded host range, we tested the transsynaptic tracing ability of recombinant vesicular stomatitis virus (rVSV) vectors in a variety of organisms. Successful infection and gene expression were achieved in a wide range of organisms, including vertebrate and invertebrate model organisms. Moreover, rVSV enabled transsynaptic tracing of neural circuitry in predictable directions dictated by the viral envelope glycoprotein (G), derived from either VSV or rabies virus (RABV). Anterograde and retrograde labeling, from initial infection and/or viral replication and transmission, was observed in Old and New World monkeys, seahorses, jellyfish, zebrafish, chickens, and mice. These vectors are widely applicable for gene delivery, afferent tract tracing, and/or directional connectivity mapping. Here, we detail the use of these vectors and provide protocols for propagating virus, changing the surface glycoprotein, and infecting multiple organisms using several injection strategies. PMID:26729030

Anterograde or Retrograde Transsynaptic Circuit Tracing in Vertebrates with Vesicular Stomatitis Virus Vectors.

PubMed

Beier, Kevin T; Mundell, Nathan A; Pan, Y Albert; Cepko, Constance L

2016-01-04

Viruses have been used as transsynaptic tracers, allowing one to map the inputs and outputs of neuronal populations, due to their ability to replicate in neurons and transmit in vivo only across synaptically connected cells. To date, their use has been largely restricted to mammals. In order to explore the use of such viruses in an expanded host range, we tested the transsynaptic tracing ability of recombinant vesicular stomatitis virus (rVSV) vectors in a variety of organisms. Successful infection and gene expression were achieved in a wide range of organisms, including vertebrate and invertebrate model organisms. Moreover, rVSV enabled transsynaptic tracing of neural circuitry in predictable directions dictated by the viral envelope glycoprotein (G), derived from either VSV or rabies virus (RABV). Anterograde and retrograde labeling, from initial infection and/or viral replication and transmission, was observed in Old and New World monkeys, seahorses, jellyfish, zebrafish, chickens, and mice. These vectors are widely applicable for gene delivery, afferent tract tracing, and/or directional connectivity mapping. Here, we detail the use of these vectors and provide protocols for propagating virus, changing the surface glycoprotein, and infecting multiple organisms using several injection strategies. Copyright © 2016 John Wiley & Sons, Inc.

Duplications and losses in gene families of rust pathogens highlight putative effectors.

PubMed

Pendleton, Amanda L; Smith, Katherine E; Feau, Nicolas; Martin, Francis M; Grigoriev, Igor V; Hamelin, Richard; Nelson, C Dana; Burleigh, J Gordon; Davis, John M

2014-01-01

Rust fungi are a group of fungal pathogens that cause some of the world's most destructive diseases of trees and crops. A shared characteristic among rust fungi is obligate biotrophy, the inability to complete a lifecycle without a host. This dependence on a host species likely affects patterns of gene expansion, contraction, and innovation within rust pathogen genomes. The establishment of disease by biotrophic pathogens is reliant upon effector proteins that are encoded in the fungal genome and secreted from the pathogen into the host's cell apoplast or within the cells. This study uses a comparative genomic approach to elucidate putative effectors and determine their evolutionary histories. We used OrthoMCL to identify nearly 20,000 gene families in proteomes of 16 diverse fungal species, which include 15 basidiomycetes and one ascomycete. We inferred patterns of duplication and loss for each gene family and identified families with distinctive patterns of expansion/contraction associated with the evolution of rust fungal genomes. To recognize potential contributors for the unique features of rust pathogens, we identified families harboring secreted proteins that: (i) arose or expanded in rust pathogens relative to other fungi, or (ii) contracted or were lost in rust fungal genomes. While the origin of rust fungi appears to be associated with considerable gene loss, there are many gene duplications associated with each sampled rust fungal genome. We also highlight two putative effector gene families that have expanded in Cqf that we hypothesize have roles in pathogenicity.

Self-mating in the definitive host potentiates clonal outbreaks of the apicomplexan parasites Sarcocystis neurona and Toxoplasma gondii.

PubMed

Wendte, Jered M; Miller, Melissa A; Lambourn, Dyanna M; Magargal, Spencer L; Jessup, David A; Grigg, Michael E

2010-12-23

Tissue-encysting coccidia, including Toxoplasma gondii and Sarcocystis neurona, are heterogamous parasites with sexual and asexual life stages in definitive and intermediate hosts, respectively. During its sexual life stage, T. gondii reproduces either by genetic out-crossing or via clonal amplification of a single strain through self-mating. Out-crossing has been experimentally verified as a potent mechanism capable of producing offspring possessing a range of adaptive and virulence potentials. In contrast, selfing and other life history traits, such as asexual expansion of tissue-cysts by oral transmission among intermediate hosts, have been proposed to explain the genetic basis for the clonal population structure of T. gondii. In this study, we investigated the contributing roles self-mating and sexual recombination play in nature to maintain clonal population structures and produce or expand parasite clones capable of causing disease epidemics for two tissue encysting parasites. We applied high-resolution genotyping against strains isolated from a T. gondii waterborne outbreak that caused symptomatic disease in 155 immune-competent people in Brazil and a S. neurona outbreak that resulted in a mass mortality event in Southern sea otters. In both cases, a single, genetically distinct clone was found infecting outbreak-exposed individuals. Furthermore, the T. gondii outbreak clone was one of several apparently recombinant progeny recovered from the local environment. Since oocysts or sporocysts were the infectious form implicated in each outbreak, the expansion of the epidemic clone can be explained by self-mating. The results also show that out-crossing preceded selfing to produce the virulent T. gondii clone. For the tissue encysting coccidia, self-mating exists as a key adaptation potentiating the epidemic expansion and transmission of newly emerged parasite clones that can profoundly shape parasite population genetic structures or cause devastating disease outbreaks.

Genetic evolution of influenza H9N2 viruses isolated from various hosts in China from 1994 to 2013

PubMed Central

Li, Chong; Wang, Shuoguo; Bing, Guoxia; Carter, Robert A; Wang, Zejiang; Wang, Jinliang; Wang, Chenxi; Wang, Lan; Wu, Gang; Webster, Robert G; Wang, Yongqiang; Sun, Honglei; Sun, Yipeng; Liu, Jinhua; Pu, Juan

2017-01-01

Influenza H9N2 subtype viruses and their reassortants (such as H7N9) are posing increasing threats to birds and humans in China. During 2009–2013, multiple novel subtype viruses with H9N2 original genes emerged in China. Yet, the genetic evolution of H9N2 viruses in various host organisms in China has not been systematically investigated since 2009. In the present study, we performed large-scale sequence analysis of H9N2 viral genomes from public databases, representing the spectrum of viruses isolated from birds, mammals and humans in China from 1994 to 2013, and updated the clade classification for each segment. We identified 117 distinct genotypes in 730 H9N2 viruses. We analyzed the sequences of all eight segments in each virus and found three important time points: the years 2000, 2006 and 2010. In the periods divided by these years, genotypic diversity, geographic distribution and host range changed considerably. Genotypic diversity fluctuated greatly in 2000 and 2006. Since 2010, a single genotype became predominant in poultry throughout China, and the eastern coastal region became the newly identified epidemic center. Throughout their 20-year prevalence in China, H9N2 influenza viruses have emerged and adapted from aquatic birds to chickens. The minor avian species and wild birds exacerbated H9N2 genotypes by providing diversified genes, and chickens were the most prevalent vector in which the viruses evolved and expanded their prevalence. It is the necessity for surveillance and disease control on live-bird markets, poultry farms and wild-bird habitats in China. PMID:29184157

Genetic evolution of influenza H9N2 viruses isolated from various hosts in China from 1994 to 2013.

PubMed

Li, Chong; Wang, Shuoguo; Bing, Guoxia; Carter, Robert A; Wang, Zejiang; Wang, Jinliang; Wang, Chenxi; Wang, Lan; Wu, Gang; Webster, Robert G; Wang, Yongqiang; Sun, Honglei; Sun, Yipeng; Liu, Jinhua; Pu, Juan

2017-11-29

Influenza H9N2 subtype viruses and their reassortants (such as H7N9) are posing increasing threats to birds and humans in China. During 2009-2013, multiple novel subtype viruses with H9N2 original genes emerged in China. Yet, the genetic evolution of H9N2 viruses in various host organisms in China has not been systematically investigated since 2009. In the present study, we performed large-scale sequence analysis of H9N2 viral genomes from public databases, representing the spectrum of viruses isolated from birds, mammals and humans in China from 1994 to 2013, and updated the clade classification for each segment. We identified 117 distinct genotypes in 730 H9N2 viruses. We analyzed the sequences of all eight segments in each virus and found three important time points: the years 2000, 2006 and 2010. In the periods divided by these years, genotypic diversity, geographic distribution and host range changed considerably. Genotypic diversity fluctuated greatly in 2000 and 2006. Since 2010, a single genotype became predominant in poultry throughout China, and the eastern coastal region became the newly identified epidemic center. Throughout their 20-year prevalence in China, H9N2 influenza viruses have emerged and adapted from aquatic birds to chickens. The minor avian species and wild birds exacerbated H9N2 genotypes by providing diversified genes, and chickens were the most prevalent vector in which the viruses evolved and expanded their prevalence. It is the necessity for surveillance and disease control on live-bird markets, poultry farms and wild-bird habitats in China.

Evolution of Compatibility Range in the Rice-Magnaporthe oryzae System: An Uneven Distribution of R Genes Between Rice Subspecies.

PubMed

Gallet, Romain; Fontaine, Colin; Bonnot, François; Milazzo, Joëlle; Tertois, Christophe; Adreit, Henri; Ravigné, Virginie; Fournier, Elisabeth; Tharreau, Didier

2016-04-01

Efficient strategies for limiting the impact of pathogens on crops require a good understanding of the factors underlying the evolution of compatibility range for the pathogens and host plants, i.e., the set of host genotypes that a particular pathogen genotype can infect and the set of pathogen genotypes that can infect a particular host genotype. Until now, little is known about the evolutionary and ecological factors driving compatibility ranges in systems implicating crop plants. We studied the evolution of host and pathogen compatibility ranges for rice blast disease, which is caused by the ascomycete Magnaporthe oryzae. We challenged 61 rice varieties from three rice subspecies with 31 strains of M. oryzae collected worldwide from all major known genetic groups. We determined the compatibility range of each plant variety and pathogen genotype and the severity of each plant-pathogen interaction. Compatibility ranges differed between rice subspecies, with the most resistant subspecies selecting for pathogens with broader compatibility ranges and the least resistant subspecies selecting for pathogens with narrower compatibility ranges. These results are consistent with a nested distribution of R genes between rice subspecies.

Host range, immunity and antigenic properties of lambdoid coliphage HK97.

PubMed

Dhillon, E K; Dhillon, T S; Lai, A N; Linn, S

1980-09-01

Temperate coliphage HK97 was isolated from pig dung. Although HK97 is antigenically unrelated to coliphage lambda, it has similar morphology, host range and immunity properties, and can recombine with it.

Chemical similarity between historical and novel host plants promotes range and host expansion of the mountain pine beetle in a naïve host ecosystem.

PubMed

Erbilgin, Nadir; Ma, Cary; Whitehouse, Caroline; Shan, Bin; Najar, Ahmed; Evenden, Maya

2014-02-01

Host plant secondary chemistry can have cascading impacts on host and range expansion of herbivorous insect populations. We investigated the role of host secondary compounds on pheromone production by the mountain pine beetle (Dendroctonus ponderosae) (MPB) and beetle attraction in response to a historical (lodgepole pine, Pinus contorta var. latifolia) and a novel (jack pine, Pinus banksiana) hosts, as pheromones regulate the host colonization process. Beetles emit the same pheromones from both hosts, but more trans-verbenol, the primary aggregation pheromone, was emitted by female beetles on the novel host. The phloem of the novel host contains more α-pinene, a secondary compound that is the precursor for trans-verbenol production in beetle, than the historical host. Beetle-induced emission of 3-carene, another secondary compound found in both hosts, was also higher from the novel host. Field tests showed that the addition of 3-carene to the pheromone mixture mimicking the aggregation pheromones produced from the two host species increased beetle capture. We conclude that chemical similarity between historical and novel hosts has facilitated host expansion of MPB in jack pine forests through the exploitation of common host secondary compounds for pheromone production and aggregation on the hosts. Furthermore, broods emerging from the novel host were larger in terms of body size. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Zoonotic infections in Alaska: disease prevalence, potential impact of climate change and recommended actions for earlier disease detection, research, prevention and control

PubMed Central

Hueffer, Karsten; Parkinson, Alan J.; Gerlach, Robert

2013-01-01

Over the last 60 years, Alaska's mean annual temperature has increased by 1.6°C, more than twice the rate of the rest of the United States. As a result, climate change impacts are more pronounced here than in other regions of the United States. Warmer temperatures may allow some infected host animals to survive winters in larger numbers, increase their population and expand their range of habitation thus increasing the opportunity for transmission of infection to humans. Subsistence hunting and gathering activities may place rural residents of Alaska at a greater risk of acquiring zoonotic infections than urban residents. Known zoonotic diseases that occur in Alaska include brucellosis, toxoplasmosis, trichinellosis, giardiasis/cryptosporidiosis, echinococcosis, rabies and tularemia. Actions for early disease detection, research and prevention and control include: (1) determining baseline levels of infection and disease in both humans and host animals; (2) conducting more research to understand the ecology of infection in the Arctic environment; (3) improving active and passive surveillance systems for infection and disease in humans and animals; (4) improving outreach, education and communication on climate-sensitive infectious diseases at the community, health and animal care provider levels; and (5) improving coordination between public health and animal health agencies, universities and tribal health organisations. PMID:23399790

Improving mycoinsecticides for insect biological control.

PubMed

Ortiz-Urquiza, Almudena; Luo, Zhibing; Keyhani, Nemat O

2015-02-01

The desire for decreased reliance on chemical pesticides continues to fuel interest in alternative means for pest control including the use of naturally occurring microbial insect pathogens. Insects, as vectors of disease causing agents or as agricultural pests, are responsible for millions of deaths and significant economic losses worldwide, placing stresses on productivity (GDP) and human health and welfare. In addition, alterations in climate change are likely to affect insect ranges, expanding their access to previously constrained geographic areas, a potentially worrisome outcome. Metarhizium anisopliae and Beauveria bassiana, two cosmopolitan fungal pathogens of insects found in almost all ecosystems, are the most commonly applied mycoinsecticides for a variety of insect control purposes. The availability of the complete genomes for both organisms coupled to robust technologies for their transformation has led to several advances in engineering these fungi for greater efficacy and/or utility in pest control applications. Here, we will provide an overview of the fungal-insect and fungal-plant interactions that occur and highlight recent advances in the genetic engineering of these fungi. The latter work has resulted in the development of strains displaying (1) increased resistance to abiotic stress, (2) increased cuticular targeting and degradation, (3) increased virulence via expression of insecticidal protein/peptide toxins, (4) the ability to block transmission of disease causing agents, and (5) the ability to target specific insect hosts, decrease host fecundity, and/or alter insect behaviors.

A review of West Nile and Usutu virus co-circulation in Europe: how much do transmission cycles overlap?

PubMed

Nikolay, Birgit

2015-10-01

Due to the increasing global spread of arboviruses, the geographic extent of virus co-circulation is expanding. This complicates the diagnosis of febrile conditions and can have direct effects on the epidemiology. As previously demonstrated, subsequent infections by two closely related viruses, such as those belonging to the Japanese encephalitis virus (JEV) serocomplex, can lead to partial or complete cross-immunity, altering the risk of infections or the outcome of disease. Two flaviviruses that may interact at population level are West Nile virus (WNV) and Usutu virus (USUV). These pathogens have antigenic cross-reactivity and affect human and animal populations throughout Europe. This systematic review investigates the overlap of WNV and USUV transmission cycles, not only geographically but also in terms of host and vector ranges. Co-circulation of WNV and USUV was reported in 10 countries and the viruses were found to infect 34 common bird species belonging to 11 orders. Moreover, four mosquito species are potential vectors for both viruses. Taken together, these data suggest that WNV and USUV transmission overlaps substantially in Europe and highlight the importance of further studies investigating the interactions between the two viruses within host and vector populations. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Synthetic biology approaches to fluorinated polyketides

PubMed Central

Thuronyi, Benjamin W.; Chang, Michelle C. Y.

2016-01-01

Conspectus The catalytic diversity of living systems offers a broad range of opportunities for developing new methods to produce small molecule targets such as fuels, materials, and pharmaceuticals. In addition to providing cost-effective and renewable methods for large-scale commercial processes, the exploration of the unusual chemical phenotypes found in living organisms can also enable the expansion of chemical space for discovery of novel function by combining orthogonal attributes from both synthetic and biological chemistry. In this context, we have focused on the development of new fluorine chemistry using synthetic biology approaches. While fluorine has become an important feature in compounds of synthetic origin, the scope of biological fluorine chemistry in living systems is limited, with fewer than 20 organofluorine natural products identified to date. In order to expand the diversity of biosynthetically accessible organofluorines, we have begun to develop methods for the site-selective introduction of fluorine into complex natural products by engineering biosynthetic machinery to incorporate fluorinated building blocks. To gain insight into how both enzyme active sites and metabolic pathways can be evolved to manage and select for fluorinated compounds, we have studied one of the only characterized natural hosts for organofluorine biosynthesis, the soil microbe Streptomyces cattleya. This information provides a template for designing engineered organofluorine enzymes, pathways, and hosts and has allowed us to initiate construction of enzymatic and cellular pathways for the production of fluorinated polyketides. PMID:25719427

Copper-catalyzed azide-alkyne cycloaddition (click chemistry)-based Detection of Global Pathogen-host AMPylation on Self-assembled Human Protein Microarrays*

PubMed Central

Yu, Xiaobo; Woolery, Andrew R.; Luong, Phi; Hao, Yi Heng; Grammel, Markus; Westcott, Nathan; Park, Jin; Wang, Jie; Bian, Xiaofang; Demirkan, Gokhan; Hang, Howard C.; Orth, Kim; LaBaer, Joshua

2014-01-01

AMPylation (adenylylation) is a recently discovered mechanism employed by infectious bacteria to regulate host cell signaling. However, despite significant effort, only a few host targets have been identified, limiting our understanding of how these pathogens exploit this mechanism to control host cells. Accordingly, we developed a novel nonradioactive AMPylation screening platform using high-density cell-free protein microarrays displaying human proteins produced by human translational machinery. We screened 10,000 unique human proteins with Vibrio parahaemolyticus VopS and Histophilus somni IbpAFic2, and identified many new AMPylation substrates. Two of these, Rac2, and Rac3, were confirmed in vivo as bona fide substrates during infection with Vibrio parahaemolyticus. We also mapped the site of AMPylation of a non-GTPase substrate, LyGDI, to threonine 51, in a region regulated by Src kinase, and demonstrated that AMPylation prevented its phosphorylation by Src. Our results greatly expanded the repertoire of potential host substrates for bacterial AMPylators, determined their recognition motif, and revealed the first pathogen-host interaction AMPylation network. This approach can be extended to identify novel substrates of AMPylators with different domains or in different species and readily adapted for other post-translational modifications. PMID:25073739

Host specificity and coevolution of Flavobacteriaceae endosymbionts within the siphonous green seaweed Bryopsis.

PubMed

Hollants, Joke; Leliaert, Frederik; Verbruggen, Heroen; De Clerck, Olivier; Willems, Anne

2013-06-01

The siphonous green seaweed Bryopsis harbors complex intracellular bacterial communities. Previous studies demonstrated that certain species form close, obligate associations with Flavobacteriaceae. A predominant imprint of host evolutionary history on the presence of these bacteria suggests a highly specialized association. In this study we elaborate on previous results by expanding the taxon sampling and testing for host-symbiont coevolution Therefore, we optimized a PCR protocol to directly and specifically amplify Flavobacteriaceae endosymbiont 16S rRNA gene sequences, which allowed us to screen a large number of algal samples without the need for cultivation or surface sterilization. We analyzed 146 Bryopsis samples, and 92 additional samples belonging to the Bryopsidales and other orders within the class Ulvophyceae. Results indicate that the Flavobacteriaceae endosymbionts are restricted to Bryopsis, and only occur within specific, warm-temperate and tropical clades of the genus. Statistical analyses (AMOVA) demonstrate a significant non-random host-symbiont association. Comparison of bacterial 16S rRNA and Bryopsis rbcL phylogenies, however, reveal complex host-symbiont evolutionary associations, whereby closely related hosts predominantly harbor genetically similar endosymbionts. Bacterial genotypes are rarely confined to a single Bryopsis species and most Bryopsis species harbored several Flavobacteriaceae, obscuring a clear pattern of coevolution. Copyright © 2013 Elsevier Inc. All rights reserved.

Host shifts enhance diversification of ectomycorrhizal fungi: diversification rate analysis of the ectomycorrhizal fungal genera Strobilomyces and Afroboletus with an 80-gene phylogeny.

PubMed

Sato, Hirotoshi; Tanabe, Akifumi S; Toju, Hirokazu

2017-04-01

Mutualisms with new host lineages can provide symbionts with novel ecological opportunities to expand their geographical distribution, thereby leading to evolutionary diversification. Because ectomycorrhizal (ECM) fungi provide ideal opportunities to test the relationship between host shifts and diversification, we tested whether mutualism with new host lineages could increase the diversification rates of ECM fungi. Using a Bayesian tree inferred from 23 027-base nucleotide sequences of 80 single-copy genes, we tested whether the diversification rate had changed through host-shift events in the monophyletic clade containing the ECM fungal genera Strobilomyces and Afroboletus. The results indicated that these fungi were initially associated with Caesalpinioideae/Monotoideae in Africa, acquired associations with Dipterocarpoideae in tropical Asia, and then switched to Fagaceae/Pinaceae and Nothofagaceae/Eucalyptus. Fungal lineages associated with Fagaceae/Pinaceae were inferred to have approximately four-fold and two-fold greater diversification rates than those associated with Caesalpinioideae/Monotoideae and Dipterocarpoideae or Nothofagaceae/Eucalyptus, respectively. Moreover, the diversification rate shift was inferred to follow the host shift to Fagaceae/Pinaceae. Our study suggests that host-shift events, particularly those occurring with respect to Fagaceae/Pinaceae, can provide ecological opportunities for the rapid diversification of Strobilomyces-Afroboletus. Although further studies are needed for generalization, we propose a possible diversification scenario of ECM fungi. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Transcriptome of an Armillaria root disease pathogen reveals candidate genes involved in host substrate utilization at the host­-pathogen interface

Treesearch

A. L. Ross-Davis; J. E. Stewart; J. W. Hanna; M.-S. Kim; B. J. Knaus; R. Cronn; H. Rai; B. A. Richardson; G. I. McDonald; N. B. Klopfenstein

2013-01-01

Armillaria species display diverse ecological roles ranging from beneficial saprobe to virulent pathogen. Armillaria solidipes (formerly A. ostoyae), a causal agent of Armillaria root disease, is a virulent primary pathogen with a broad host range of woody plants across the Northern Hemisphere. This white-rot pathogen grows between trees as rhizomorphs and attacks...

Which morphological characteristics are most influenced by the host matrix in downy mildews? A case study in Pseudoperonospora cubensis.

PubMed

Runge, Fabian; Ndambi, Beninweck; Thines, Marco

2012-01-01

Before the advent of molecular phylogenetics, species concepts in the downy mildews, an economically important group of obligate biotrophic oomycete pathogens, have mostly been based upon host range and morphology. While molecular phylogenetic studies have confirmed a narrow host range for many downy mildew species, others, like Pseudoperonospora cubensis affect even different genera. Although often morphological differences were found for new, phylogenetically distinct species, uncertainty prevails regarding their host ranges, especially regarding related plants that have been reported as downy mildew hosts, but were not included in the phylogenetic studies. In these cases, the basis for deciding if the divergence in some morphological characters can be deemed sufficient for designation as separate species is uncertain, as observed morphological divergence could be due to different host matrices colonised. The broad host range of P. cubensis (ca. 60 host species) renders this pathogen an ideal model organism for the investigation of morphological variations in relation to the host matrix and to evaluate which characteristics are best indicators for conspecificity or distinctiveness. On the basis of twelve morphological characterisitcs and a set of twelve cucurbits from five different Cucurbitaceae tribes, including the two species, Cyclanthera pedata and Thladiantha dubia, hitherto not reported as hosts of P. cubensis, a significant influence of the host matrix on pathogen morphology was found. Given the high intraspecific variation of some characteristics, also their plasticity has to be taken into account. The implications for morphological species determination and the confidence limits of morphological characteristics are discussed. For species delimitations in Pseudoperonospora it is shown that the ratio of the height of the first ramification to the sporangiophore length, ratio of the longer to the shorter ultimate branchlet, and especially the length and width of sporangia, as well as, with some reservations, their ratio, are the most suitable characteristics for species delimitation.

Which Morphological Characteristics Are Most Influenced by the Host Matrix in Downy Mildews? A Case Study in Pseudoperonospora cubensis

PubMed Central

Runge, Fabian; Ndambi, Beninweck; Thines, Marco

2012-01-01

Before the advent of molecular phylogenetics, species concepts in the downy mildews, an economically important group of obligate biotrophic oomycete pathogens, have mostly been based upon host range and morphology. While molecular phylogenetic studies have confirmed a narrow host range for many downy mildew species, others, like Pseudoperonospora cubensis affect even different genera. Although often morphological differences were found for new, phylogenetically distinct species, uncertainty prevails regarding their host ranges, especially regarding related plants that have been reported as downy mildew hosts, but were not included in the phylogenetic studies. In these cases, the basis for deciding if the divergence in some morphological characters can be deemed sufficient for designation as separate species is uncertain, as observed morphological divergence could be due to different host matrices colonised. The broad host range of P. cubensis (ca. 60 host species) renders this pathogen an ideal model organism for the investigation of morphological variations in relation to the host matrix and to evaluate which characteristics are best indicators for conspecificity or distinctiveness. On the basis of twelve morphological characterisitcs and a set of twelve cucurbits from five different Cucurbitaceae tribes, including the two species, Cyclanthera pedata and Thladiantha dubia, hitherto not reported as hosts of P. cubensis, a significant influence of the host matrix on pathogen morphology was found. Given the high intraspecific variation of some characteristics, also their plasticity has to be taken into account. The implications for morphological species determination and the confidence limits of morphological characteristics are discussed. For species delimitations in Pseudoperonospora it is shown that the ratio of the height of the first ramification to the sporangiophore length, ratio of the longer to the shorter ultimate branchlet, and especially the length and width of sporangia, as well as, with some reservations, their ratio, are the most suitable characteristics for species delimitation. PMID:23166582

Patterns of host specificity among the helminth parasite fauna of freshwater siluriforms: testing the biogeographical core parasite fauna hypothesis.

PubMed

Rosas-Valdez, Rogelio; de León, Gerardo Pérez-Ponce

2011-04-01

Host specificity plays an essential role in shaping the evolutionary history of host-parasite associations. In this study, an index of host specificity recently proposed was used to test, quantitatively, the hypothesis that some groups of parasites are characteristics of some host fish families along their distribution range. A database with all published records on the helminth parasites of freshwater siluriforms of Mexico was used. The host specificity index was used considering its advantage to measure the taxonomic heterogeneity of the host assemblages and its appropriateness for unequal sampling data. The helminth parasite fauna of freshwater siluriforms in Mexico seems to be specific for different host taxonomic categories. However, a relatively high number of species (47% of the total helminth fauna) is specific to their respective host family. This result provides further corroboration for the biogeographic hypothesis of the core helminth fauna proposed previously. The statistical values for host specificity obtained herein seem to be independent of host range. However, the accurate taxonomic identification of the parasites is fundamental for the evaluation of host specificity and the accurate evolutionary interpretation of this phenomenon.

Separating the signal from the noise: Expanding flow cytometry into the sub-micron range.

EPA Science Inventory

Cytometry Part A Special Section: Separating the signal from the noise: Expanding flow cytometry into the sub-micron range. The current Cytometry Part A Special Section presents three studies that utilize cytometers to study sub-micron particles. The three studies involve the 1...

Regional collapse of symbiotic specificity between lucanid beetles and canestriniid mites

NASA Astrophysics Data System (ADS)

Okabe, Kimiko; Masuya, Hayato; Kanzaki, Natusmi; Taki, Hisatomo

2012-11-01

The intensity of interspecific interactions between hosts and symbionts varies among populations of each organism because of differences in the biotic and abiotic environment. We found geographic mosaics in associations between lucanid beetles ( Dorcus rectus and Dorcus striatipennis) and symbiotic mites ( Haitlingeria sp. and Sandrophela sp., respectively) that were caused by the collapse of host specificity in the northern part of Japan. Haitlingeria sp. was only collected from the surface of the exoskeleton of D. rectus in south and central Japan. Sandrophela sp. showed host specificity in southern to central Japan but was found on both beetle species in areas where Haitlingeria sp. was not found. Because Haitlingeria sp. was able to reproduce on D. rectus collected from Haitlingeria-free regions and no significant differences were observed in average temperature between the host-specific and nonspecific regions bordering on each other, we suggest that the expansion of Haitlingeria sp. in the north has been limited for unknown reasons. When both mites were placed together on D. rectus, only Haitlingeria sp. reproduced, probably because it killed Sandrophela sp., especially juveniles. Thus, we conclude that Sandrophela sp. has expanded its host use to include D. rectus in areas where Haitlingeria sp. is absent. We hypothesise that false host specificity in the canestriniids has been maintained by habitat isolation and/or aggressive behaviour toward competitors. We suggest that host-specific canestriniids provide benefits to hosts that do not develop countermeasures to exclude micro- or macroparasites from their surfaces.

Evasion and Immuno-Endocrine Regulation in Parasite Infection: Two Sides of the Same Coin in Chagas Disease?

PubMed

Morrot, Alexandre; Villar, Silvina R; González, Florencia B; Pérez, Ana R

2016-01-01

Chagas disease is a serious illness caused by the protozoan parasite Trypanosoma cruzi. Nearly 30% of chronically infected people develop cardiac, digestive, or mixed alterations, suggesting a broad range of host-parasite interactions that finally impact upon chronic disease outcome. The ability of T. cruzi to persist and cause pathology seems to depend on diverse factors like T. cruzi strains, the infective load and the route of infection, presence of virulence factors, the parasite capacity to avoid protective immune response, the strength and type of host defense mechanisms and the genetic background of the host. The host-parasite interaction is subject to a constant neuro-endocrine regulation that is thought to influence the adaptive immune system, and as the infection proceeds it can lead to a broad range of outcomes, ranging from pathogen elimination to its continued persistence in the host. In this context, T. cruzi evasion strategies and host defense mechanisms can be envisioned as two sides of the same coin, influencing parasite persistence and different outcomes observed in Chagas disease. Understanding how T. cruzi evade host's innate and adaptive immune response will provide important clues to better dissect mechanisms underlying the pathophysiology of Chagas disease.

Silage Collected from Dairy Farms Harbors an Abundance of Listeriaphages with Considerable Host Range and Genome Size Diversity

PubMed Central

Vongkamjan, Kitiya; Switt, Andrea Moreno; den Bakker, Henk C.; Fortes, Esther D.

2012-01-01

Since the food-borne pathogen Listeria monocytogenes is common in dairy farm environments, it is likely that phages infecting this bacterium (“listeriaphages”) are abundant on dairy farms. To better understand the ecology and diversity of listeriaphages on dairy farms and to develop a diverse phage collection for further studies, silage samples collected on two dairy farms were screened for L. monocytogenes and listeriaphages. While only 4.5% of silage samples tested positive for L. monocytogenes, 47.8% of samples were positive for listeriaphages, containing up to >1.5 × 104 PFU/g. Host range characterization of the 114 phage isolates obtained, with a reference set of 13 L. monocytogenes strains representing the nine major serotypes and four lineages, revealed considerable host range diversity; phage isolates were classified into nine lysis groups. While one serotype 3c strain was not lysed by any phage isolates, serotype 4 strains were highly susceptible to phages and were lysed by 63.2 to 88.6% of phages tested. Overall, 12.3% of phage isolates showed a narrow host range (lysing 1 to 5 strains), while 28.9% of phages represented broad host range (lysing ≥11 strains). Genome sizes of the phage isolates were estimated to range from approximately 26 to 140 kb. The extensive host range and genomic diversity of phages observed here suggest an important role of phages in the ecology of L. monocytogenes on dairy farms. In addition, the phage collection developed here has the potential to facilitate further development of phage-based biocontrol strategies (e.g., in silage) and other phage-based tools. PMID:23042180

Living on the Edge: Parasite Prevalence Changes Dramatically across a Range Edge in an Invasive Gecko.

PubMed

Coates, Andrew; Barnett, Louise K; Hoskin, Conrad; Phillips, Ben L

2017-02-01

Species interactions can determine range limits, and parasitism is the most intimate of such interactions. Intriguingly, the very conditions on range edges likely change host-parasite dynamics in nontrivial ways. Range edges are often associated with clines in host density and with environmental transitions, both of which may affect parasite transmission. On advancing range edges, founder events and fitness/dispersal costs of parasitism may also cause parasites to be lost on range edges. Here we examine the prevalence of three species of parasite across the range edge of an invasive gecko, Hemidactylus frenatus, in northeastern Australia. The gecko's range edge spans the urban-woodland interface at the edge of urban areas. Across this edge, gecko abundance shows a steep decline, being lower in the woodland. Two parasite species (a mite and a pentastome) are coevolved with H. frenatus, and these species become less prevalent as the geckos become less abundant. A third species of parasite (another pentastome) is native to Australia and has no coevolutionary history with H. frenatus. This species became more prevalent as the geckos become less abundant. These dramatic shifts in parasitism (occurring over 3.5 km) confirm that host-parasite dynamics can vary substantially across the range edge of this gecko host.

Short-sighted evolution of virulence in parasitic honeybee workers ( Apis mellifera capensis Esch.)

NASA Astrophysics Data System (ADS)

Moritz, Robin F. A.; Pirk, Christian W. W.; Hepburn, H. Randall; Neumann, Peter

2008-06-01

The short-sighted selection hypothesis for parasite virulence predicts that winners of within-host competition are poorer at transmission to new hosts. Social parasitism by self-replicating, female-producing workers occurs in the Cape honeybee Apis mellifera capensis, and colonies of other honeybee subspecies are susceptible hosts. We found high within-host virulence but low transmission rates in a clone of social parasitic A. m. capensis workers invading the neighbouring subspecies A. m. scutellata. In contrast, parasitic workers from the endemic range of A. m. capensis showed low within-host virulence but high transmission rates. This suggests a short-sighted selection scenario for the host-parasite co-evolution in the invasive range of the Cape honeybee, probably facilitated by beekeeping-assisted parasite transmission in apiaries.

Warthin tumor presenting as a fungal abscess in an immunocompetent host: case report and review of the literature.

PubMed

Leibowitz, Jason M; Montone, Kathleen T; Basu, Devraj

2010-01-01

Fungal abscesses of the parotid gland are rare, and cases arising within parotid neoplasms have not been described previously. This report conveys our experience managing such an entity, which is further distinguished by its occurrence in an immunocompetent host. A 59-year-old man experienced multiple recurrences of a parotid fungal abscess requiring repeated drainage procedures. Definitive excision ultimately demonstrated Candida glabrata infecting a Warthin tumor. This case is the first report of a parotid neoplasm presenting as a fungal abscess. It contributes to the scant literature on fungal abscesses of the parotid, which previously has only been described in debilitated hosts and without an associated neoplasm. The case also expands the spectrum of disease associated with C. glabrata. Warthin tumor may be an occult etiology for a parotid fungal abscess, and definitive diagnosis and therapy may require parotidectomy.

Complex archaea that bridge the gap between prokaryotes and eukaryotes

PubMed Central

Martijn, Joran; Lind, Anders E.; van Eijk, Roel; Schleper, Christa; Guy, Lionel; Ettema, Thijs J. G.

2015-01-01

The origin of the eukaryotic cell remains one of the most contentious puzzles in modern biology. Recent studies have provided support for the emergence of the eukaryotic host cell from within the archaeal domain of life, but the identity and nature of the putative archaeal ancestor remain a subject of debate. Here we describe the discovery of ‘Lokiarchaeota’, a novel candidate archaeal phylum, which forms a monophyletic group with eukaryotes in phylogenomic analyses, and whose genomes encode an expanded repertoire of eukaryotic signature proteins that are suggestive of sophisticated membrane remodelling capabilities. Our results provide strong support for hypotheses in which the eukaryotic host evolved from a bona fide archaeon, and demonstrate that many components that underpin eukaryote-specific features were already present in that ancestor. This provided the host with a rich genomic ‘starter-kit’ to support the increase in the cellular and genomic complexity that is characteristic of eukaryotes. PMID:25945739

Analysis of physical activity and acculturation among Turkish migrants in Germany and England (.).

PubMed

Koca, Canan; Lapa, Tennur Yerlisu

2014-12-01

Recent literature shows that migrant populations in Western countries are generally less physically active than their host populations. The purpose of the present study was to expand research investigating associations between physical activity (PA) and acculturation and their relationship with several socio-demographic factors among Turkish migrants in Germany and England. The sample consisted of 521 Turkish migrants. Migrant generation, length of residence, and language proficiency were used as indicators of acculturation. Acculturation was not associated with PA among migrants in Germany and England. PA of migrants was significantly associated with migrant's host country, age, sex, marital status, and education. The total PA of migrants in Germany was higher than that of migrants in England; the large majority of females in both Germany and England had low PA, whereas most males had moderate PA. Seemingly, PA in Turkish migrant populations will not necessarily increase as a result of greater acculturation to the host society.

Redescription of Gyropus parvus (Ewing, 1924) (Insecta: Phthiraptera: Amblycera: Gyropidae) from tucos-tucos (Rodentia: Ctenomyidae: Ctenomys ) in Patagonia, Argentina.

PubMed

Martino, N S; Romero, M D; Castro, D C

2010-02-01

A detailed redescription of Gyropus parvus (Insecta: Phthiraptera: Amblycera: Gyropidae) is given based on specimens collected from the type host, Ctenomys colburni Allen 1903 , and the type locality, Estancia Huanuluán, Provincia de Rio Negro, Argentina. We expand and provide new chaetotaxy. New scanning electron microscopy images showing microstructural details of adults and eggs of G. parvus obtained from topotype specimens are included. Sexual dimorphism was mainly shown by differences in body size and abdominal chaetotaxy, with females being 17.5% larger than males and with more setae in each cluster. Significant differences between males and females were also observed in sternal plate measurements. Features described here show homogeneity within type host population. This information contributes to our knowledge of intra- and inter-specific variability for parasite populations. Our investigation constitutes the first collection of G. parvus from the type host and locality since it was described.

Virocell Metabolism: Metabolic Innovations During Host-Virus Interactions in the Ocean.

PubMed

Rosenwasser, Shilo; Ziv, Carmit; Creveld, Shiri Graff van; Vardi, Assaf

2016-10-01

Marine viruses are considered to be major ecological, evolutionary, and biogeochemical drivers of the marine environment, responsible for nutrient recycling and determining species composition. Viruses can re-shape their host's metabolic network during infection, generating the virocell-a unique metabolic state that supports their specific requirement. Here we discuss the concept of 'virocell metabolism' and its formation by rewiring of host-encoded metabolic networks, or by introducing virus-encoded auxiliary metabolic genes which provide the virocell with novel metabolic capabilities. The ecological role of marine viruses is commonly assessed by their relative abundance and phylogenetic diversity, lacking the ability to assess the dynamics of active viral infection. The new ability to define a unique metabolic state of the virocell will expand the current virion-centric approaches in order to quantify the impact of marine viruses on microbial food webs. Copyright © 2016. Published by Elsevier Ltd.

Fierce Competition between Toxoplasma and Chlamydia for Host Cell Structures in Dually Infected Cells

PubMed Central

Romano, Julia D.; de Beaumont, Catherine; Carrasco, Jose A.; Ehrenman, Karen; Bavoil, Patrik M.

2013-01-01

The prokaryote Chlamydia trachomatis and the protozoan Toxoplasma gondii, two obligate intracellular pathogens of humans, have evolved a similar modus operandi to colonize their host cell and salvage nutrients from organelles. In order to gain fundamental knowledge on the pathogenicity of these microorganisms, we have established a cell culture model whereby single fibroblasts are coinfected by C. trachomatis and T. gondii. We previously reported that the two pathogens compete for the same nutrient pools in coinfected cells and that Toxoplasma holds a significant competitive advantage over Chlamydia. Here we have expanded our coinfection studies by examining the respective abilities of Chlamydia and Toxoplasma to co-opt the host cytoskeleton and recruit organelles. We demonstrate that the two pathogen-containing vacuoles migrate independently to the host perinuclear region and rearrange the host microtubular network around each vacuole. However, Toxoplasma outcompetes Chlamydia to the host microtubule-organizing center to the detriment of the bacterium, which then shifts to a stress-induced persistent state. Solely in cells preinfected with Chlamydia, the centrosomes become associated with the chlamydial inclusion, while the Toxoplasma parasitophorous vacuole displays growth defects. Both pathogens fragment the host Golgi apparatus and recruit Golgi elements to retrieve sphingolipids. This study demonstrates that the productive infection by both Chlamydia and Toxoplasma depends on the capability of each pathogen to successfully adhere to a finely tuned developmental program that aims to remodel the host cell for the pathogen's benefit. In particular, this investigation emphasizes the essentiality of host organelle interception by intravacuolar pathogens to facilitate access to nutrients. PMID:23243063

Fierce competition between Toxoplasma and Chlamydia for host cell structures in dually infected cells.

PubMed

Romano, Julia D; de Beaumont, Catherine; Carrasco, Jose A; Ehrenman, Karen; Bavoil, Patrik M; Coppens, Isabelle

2013-02-01

The prokaryote Chlamydia trachomatis and the protozoan Toxoplasma gondii, two obligate intracellular pathogens of humans, have evolved a similar modus operandi to colonize their host cell and salvage nutrients from organelles. In order to gain fundamental knowledge on the pathogenicity of these microorganisms, we have established a cell culture model whereby single fibroblasts are coinfected by C. trachomatis and T. gondii. We previously reported that the two pathogens compete for the same nutrient pools in coinfected cells and that Toxoplasma holds a significant competitive advantage over Chlamydia. Here we have expanded our coinfection studies by examining the respective abilities of Chlamydia and Toxoplasma to co-opt the host cytoskeleton and recruit organelles. We demonstrate that the two pathogen-containing vacuoles migrate independently to the host perinuclear region and rearrange the host microtubular network around each vacuole. However, Toxoplasma outcompetes Chlamydia to the host microtubule-organizing center to the detriment of the bacterium, which then shifts to a stress-induced persistent state. Solely in cells preinfected with Chlamydia, the centrosomes become associated with the chlamydial inclusion, while the Toxoplasma parasitophorous vacuole displays growth defects. Both pathogens fragment the host Golgi apparatus and recruit Golgi elements to retrieve sphingolipids. This study demonstrates that the productive infection by both Chlamydia and Toxoplasma depends on the capability of each pathogen to successfully adhere to a finely tuned developmental program that aims to remodel the host cell for the pathogen's benefit. In particular, this investigation emphasizes the essentiality of host organelle interception by intravacuolar pathogens to facilitate access to nutrients.

Host Plant-Associated Population Variation in the Carob Moth Ectomyelois ceratoniae in Iran: A Geometric Morphometric Analysis Suggests a Nutritional Basis.

PubMed Central

Mozaffarian, Fariba; Sarafrazi, Alimorad; Ganbalani, Gadir Nouri

2007-01-01

The carob moth, Ectomyelois ceratoniae (Zeller, 1839) (Lepidoptera: Pyralidae), is the most important pest of pomegranate in Iran. As it has been rarely recorded on other host plants, control methods have mostly been focused on its populations on pomegranate. In this study, shapes and sizes of wings were compared in populations on 4 host plants (pomegranate, fig, pistachio and walnut) using a landmark-based geometric morphometric method, and analysis of partial warp scores and centroid sizes. The results showed significantly smaller wing size in populations on pomegranate and a significant host plant-associated shape difference among populations as a consequence of allometric growth. This suggests that the wing size and shape differences among test populations may not have a genetic basis and could happen because of differences in the nutritional content of host plants. The results of the analysis suggest that the female carob moth lays her eggs on host plants that provide suitable conditions for hatching. The larger size of moths on hosts other than pomegranate showed that some host plants such as fig, pistachio and walnut can provide for increased stored nutritional reserves by larvae that may result in more successful over-wintering and higher fecundity in adults. This suggests that in spite of the more extensive activity of carob moth on pomegranate in Iran, populations on other host plants can have an important effect on expanding pest population sizes in following years which should be considered in control methods. PMID:20337550

Chemical and behavioral integration of army ant-associated rove beetles - a comparison between specialists and generalists.

PubMed

von Beeren, Christoph; Brückner, Adrian; Maruyama, Munetoshi; Burke, Griffin; Wieschollek, Jana; Kronauer, Daniel J C

2018-01-01

Host-symbiont interactions are embedded in ecological communities and range from unspecific to highly specific relationships. Army ants and their arthropod guests represent a fascinating example of species-rich host-symbiont associations where host specificity ranges across the entire generalist - specialist continuum. In the present study, we compared the behavioral and chemical integration mechanisms of two extremes of the generalist - specialist continuum: generalist ant-predators in the genus Tetradonia (Staphylinidae: Aleocharinae: Athetini), and specialist ant-mimics in the genera Ecitomorpha and Ecitophya (Staphylinidae: Aleocharinae: Ecitocharini). Similar to a previous study of Tetradonia beetles, we combined DNA barcoding with morphological studies to define species boundaries in ant-mimicking beetles. This approach found four ant-mimicking species at our study site at La Selva Biological Station in Costa Rica. Community sampling of Eciton army ant parasites revealed that ant-mimicking beetles were perfect host specialists, each beetle species being associated with a single Eciton species. These specialists were seamlessly integrated into the host colony, while generalists avoided physical contact to host ants in behavioral assays. Analysis of the ants' nestmate recognition cues, i.e. cuticular hydrocarbons (CHCs), showed close similarity in CHC composition and CHC concentration between specialists and Eciton burchellii foreli host ants. On the contrary, the chemical profiles of generalists matched host profiles less well, indicating that high accuracy in chemical host resemblance is only accomplished by socially integrated species. Considering the interplay between behavior, morphology, and cuticular chemistry, specialists but not generalists have cracked the ants' social code with respect to various sensory modalities. Our results support the long-standing idea that the evolution of host-specialization in parasites is a trade-off between the range of potential host species and the level of specialization on any particular host.

The Effects of Aphid Traits on Parasitoid Host Use and Specialist Advantage

PubMed Central

Gagic, Vesna; Petrović-Obradović, Olivera; Fründ, Jochen; Kavallieratos, Nickolas G.; Athanassiou, Christos G.; Starý, Petr; Tomanović, Željko

2016-01-01

Specialization is a central concept in ecology and one of the fundamental properties of parasitoids. Highly specialized parasitoids tend to be more efficient in host-use compared to generalized parasitoids, presumably owing to the trade-off between host range and host-use efficiency. However, it remains unknown how parasitoid host specificity and host-use depends on host traits related to susceptibility to parasitoid attack. To address this question, we used data from a 13-year survey of interactions among 142 aphid and 75 parasitoid species in nine European countries. We found that only aphid traits related to local resource characteristics seem to influence the trade-off between host-range and efficiency: more specialized parasitoids had an apparent advantage (higher abundance on shared hosts) on aphids with sparse colonies, ant-attendance and without concealment, and this was more evident when host relatedness was included in calculation of parasitoid specificity. More traits influenced average assemblage specialization, which was highest in aphids that are monophagous, monoecious, large, highly mobile (easily drop from a plant), without myrmecophily, habitat specialists, inhabit non-agricultural habitats and have sparse colonies. Differences in aphid wax production did not influence parasitoid host specificity and host-use. Our study is the first step in identifying host traits important for aphid parasitoid host specificity and host-use and improves our understanding of bottom-up effects of aphid traits on aphid-parasitoid food web structure. PMID:27309729

Plant defenses against parasitic plants show similarities to those induced by herbivores and pathogens

Treesearch

Justin B. Runyon; Mark C. Mescher; Consuelo M. De Moraes

2010-01-01

Herbivores and pathogens come quickly to mind when one thinks of the biotic challenges faced by plants. Important but less appreciated enemies are parasitic plants, which can have important consequences for the fitness and survival of their hosts. Our knowledge of plant perception, signaling and response to herbivores and pathogens has expanded rapidly in recent years...

The multitrophic consequences of concurrent insect invasions: a range-expanding herbivore and its associated parasitoid affect native tritrophic interactions

USDA-ARS?s Scientific Manuscript database

Global climatic changes may lead to the arrival of range-expanding species into new environments. Species from different trophic levels sharing the same climatic niche may invade new habitats simultaneously or in quick succession, causing the formation of multiple novel interactions into native food...

The Paleoparasitology in Brazil and Findings in Human Remains from South America: A Review

PubMed Central

Novo, Shênia Patrícia Corrêa; Ferreira, Luiz Fernando

2016-01-01

The review article presents some of the history of how paleoparasitology started in Brazil, making highlight the great responsible Dr. Luiz Fernando Ferreira and Dr. Adauto Araújo, the trajectory of paleoparasitology in Brazil since 1978 and its performance in science to the present day. In sequence, it is made a presentation of parasitological findings on human remains found in archaeological sites in South America, highlighting Brazil, Argentina, Chile, and Peru, where major discoveries have occurred. Many of the parasites found in archaeological material and mentioned in this review went out of Africa with the peopling of Europe and from there they dispersed around the world, where climatic conditions allow the transmission. However, humans have acquired other parasites of animals, since humans invaded new habitats or creating new habits adopting new technologies, thus expanding its range of influence on the environment. Thus, this review article is finalized with information that explain the importance of these findings in the interaction between parasites, human host, and ambient. PMID:27853114

The Paleoparasitology in Brazil and Findings in Human Remains from South America: A Review.

PubMed

Novo, Shênia Patrícia Corrêa; Ferreira, Luiz Fernando

2016-10-01

The review article presents some of the history of how paleoparasitology started in Brazil, making highlight the great responsible Dr. Luiz Fernando Ferreira and Dr. Adauto Araújo, the trajectory of paleoparasitology in Brazil since 1978 and its performance in science to the present day. In sequence, it is made a presentation of parasitological findings on human remains found in archaeological sites in South America, highlighting Brazil, Argentina, Chile, and Peru, where major discoveries have occurred. Many of the parasites found in archaeological material and mentioned in this review went out of Africa with the peopling of Europe and from there they dispersed around the world, where climatic conditions allow the transmission. However, humans have acquired other parasites of animals, since humans invaded new habitats or creating new habits adopting new technologies, thus expanding its range of influence on the environment. Thus, this review article is finalized with information that explain the importance of these findings in the interaction between parasites, human host, and ambient.

Universal fungal vaccines

PubMed Central

Hamad, Mawieh

2012-01-01

The complex nature of fungal pathogens, the intricate host-pathogen relationship and the health status of subjects in need of antifungal vaccination continue to hamper efforts to develop fungal vaccines for clinical use. That said, the rise of the universal vaccine concept is hoped to revive fungal vaccine research by expanding the pool of vaccine candidates worthy of clinical evaluation. It can do so through antigenic commonality-based screening for vaccine candidates from a wide range of pathogens and by reassessing the sizable collection of already available experimental and approved vaccines. Development of experimental vaccines protective against multiple fungal pathogens is evidence of the utility of this concept in fungal vaccine research. However, universal fungal vaccines are not without difficulties; for instance, development of vaccines with differential effectiveness is an issue that should be addressed. Additionally, rationalizing the development of universal fungal vaccines on health or economic basis could be contentious. Herein, universal fungal vaccines are discussed in terms of their potential usefulness and possible drawbacks. PMID:22922769

Infection of Polarized MDCK Cells with Herpes Simplex Virus 1: Two Asymmetrically Distributed Cell Receptors Interact with Different Viral Proteins

NASA Astrophysics Data System (ADS)

Sears, Amy E.; McGwire, Bradford S.; Roizman, Bernard

1991-06-01

Herpes simplex virus 1 attaches to at least two cell surface receptors. In polarized epithelial (Madin-Darby canine kidney; MDCK) cells one receptor is located in the apical surface and attachment to the cells requires the presence of glycoprotein C in the virus. The second receptor is located in the basal surface and does not require the presence of glycoprotein C. Exposure of MDCK cells at either the apical or basal surface to wild-type virus yields plaques and viral products whereas infection by a glycoprotein C-negative mutant yields identical results only after exposure of MDCK cells to virus at the basal surface. Multiple receptors for viral entry into cells expand the host range of the virus. The observation that glycoprotein C-negative mutants are infectious in many nonpolarized cell lines suggests that cells in culture may express more than one receptor and explains why genes that specify the viral proteins that recognize redundant receptors, like glycoprotein C, are expendable.

Chemical reactions confined within carbon nanotubes.

PubMed

Miners, Scott A; Rance, Graham A; Khlobystov, Andrei N

2016-08-22

In this critical review, we survey the wide range of chemical reactions that have been confined within carbon nanotubes, particularly emphasising how the pairwise interactions between the catalysts, reactants, transition states and products of a particular molecular transformation with the host nanotube can be used to control the yields and distributions of products of chemical reactions. We demonstrate that nanoscale confinement within carbon nanotubes enables the control of catalyst activity, morphology and stability, influences the local concentration of reactants and products thus affecting equilibria, rates and selectivity, pre-arranges the reactants for desired reactions and alters the relative stability of isomeric products. We critically evaluate the relative advantages and disadvantages of the confinement of chemical reactions inside carbon nanotubes from a chemical perspective and describe how further developments in the controlled synthesis of carbon nanotubes and the incorporation of multifunctionality are essential for the development of this ever-expanding field, ultimately leading to the effective control of the pathways of chemical reactions through the rational design of multi-functional carbon nanoreactors.

Potential economic pests of solanaceous crops: a new species of Solanum-feeding psyllid from Australia and first record from New Zealand of Acizzia solanicola (Hemiptera: Psyllidae).

PubMed

Taylor, Gary S; Kent, Deborah S

2013-02-11

Acizzia credoensis sp. n. is described from a single population on the native plant, Solanum lasiophyllum, from semi-arid Western Australia. The host range of Acizzia solanicola Kent & Taylor, initially recorded as damaging eggplant, S. melongena, in commercial crops and gardens and on wild tobacco bush, S. mauritianum in eastern Australia, is expanded to include the following Solanaceae: rock nightshade, S. petrophilum, cape gooseberry, Physalis peruviana, and an undetermined species of angel's trumpet Brugmansia and Datura. New Zealand specimens of A. solanicola collected in early 2012 from S. mauritianum are the first record for this species from outside Australia, and possibly represent a very recent incursion. The potential for the solanaceous-inhabiting Psyllidae to vector Candidatus Liberibacter solanacearum, an economically important plant pathogen, on native Australian Solanaceae is discussed. The occurrence of A. credoensis and A. solanicola on native Australian Solanum supports the Australian origin for the solanaceous-inhabiting Acizzia psyllids.

The Expanding Family of Virophages

PubMed Central

Bekliz, Meriem; Colson, Philippe; La Scola, Bernard

2016-01-01

Virophages replicate with giant viruses in the same eukaryotic cells. They are a major component of the specific mobilome of mimiviruses. Since their discovery in 2008, five other representatives have been isolated, 18 new genomes have been described, two of which being nearly completely sequenced, and they have been classified in a new viral family, Lavidaviridae. Virophages are small viruses with approximately 35–74 nm large icosahedral capsids and 17–29 kbp large double-stranded DNA genomes with 16–34 genes, among which a very small set is shared with giant viruses. Virophages have been isolated or detected in various locations and in a broad range of habitats worldwide, including the deep ocean and inland. Humans, therefore, could be commonly exposed to virophages, although currently limited evidence exists of their presence in humans based on serology and metagenomics. The distribution of virophages, the consequences of their infection and the interactions with their giant viral hosts within eukaryotic cells deserve further research. PMID:27886075

Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeli in Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador

PubMed Central

Ocaña-Mayorga, Sofia; Aguirre-Villacis, Fernanda; Pinto, C. Miguel; Vallejo, Gustavo A.

2015-01-01

Abstract Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador. This study reports infection with T. rangeli in 18 genera of mammal hosts and five species of triatomines in three environments (domestic, peridomestic, and sylvatic). Higher infection rates were found in the sylvatic environment, in close association with Rhodnius ecuadoriensis. The results of this study extend the range of hosts infected with this parasite and the geographic range of the T. rangeli genotype KP1(−)/lineage C in South America. It was not possible to detect variation on T. rangeli from the central coastal region and southern Ecuador with the analysis of the small subunit ribosomal RNA (SSU-rRNA) gene, even though these areas are ecologically different and a phenotypic subdivision of R. ecuadoriensis has been found. R. ecuadoriensis is considered one of the most important vectors for Chagas disease transmission in Ecuador due to its wide distribution and adaptability to diverse environments. An extensive knowledge of the trypanosomes circulating in this species of triatomine, and associated mammal hosts, is important for delineating transmission dynamics and preventive measures in the endemic areas of Ecuador and Northern Peru. PMID:26645579

Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeli in Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador.

PubMed

Ocaña-Mayorga, Sofia; Aguirre-Villacis, Fernanda; Pinto, C Miguel; Vallejo, Gustavo A; Grijalva, Mario J

2015-12-01

Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador. This study reports infection with T. rangeli in 18 genera of mammal hosts and five species of triatomines in three environments (domestic, peridomestic, and sylvatic). Higher infection rates were found in the sylvatic environment, in close association with Rhodnius ecuadoriensis. The results of this study extend the range of hosts infected with this parasite and the geographic range of the T. rangeli genotype KP1(-)/lineage C in South America. It was not possible to detect variation on T. rangeli from the central coastal region and southern Ecuador with the analysis of the small subunit ribosomal RNA (SSU-rRNA) gene, even though these areas are ecologically different and a phenotypic subdivision of R. ecuadoriensis has been found. R. ecuadoriensis is considered one of the most important vectors for Chagas disease transmission in Ecuador due to its wide distribution and adaptability to diverse environments. An extensive knowledge of the trypanosomes circulating in this species of triatomine, and associated mammal hosts, is important for delineating transmission dynamics and preventive measures in the endemic areas of Ecuador and Northern Peru.

Proteomic approaches to understanding the role of the cytoskeleton in host-defense mechanisms

PubMed Central

Radulovic, Marko; Godovac-Zimmermann, Jasminka

2014-01-01

The cytoskeleton is a cellular scaffolding system whose functions include maintenance of cellular shape, enabling cellular migration, division, intracellular transport, signaling and membrane organization. In addition, in immune cells, the cytoskeleton is essential for phagocytosis. Following the advances in proteomics technology over the past two decades, cytoskeleton proteome analysis in resting and activated immune cells has emerged as a possible powerful approach to expand our understanding of cytoskeletal composition and function. However, so far there have only been a handful of studies of the cytoskeleton proteome in immune cells. This article considers promising proteomics strategies that could augment our understanding of the role of the cytoskeleton in host-defense mechanisms. PMID:21329431

Morphological variation and host range of two Ganoderma species from Papua New Guinea.

PubMed

Pilotti, Carmel A; Sanderson, Frank R; Aitken, Elizabeth A B; Armstrong, Wendy

2004-08-01

Two species of Ganoderma belonging to different subgenera which cause disease on oil palms in PNG are identified by basidiome morphology and the morphology of their basidiospores. The names G. boninense and G. tornatum have been applied. Significant pleiomorphy was observed in basidiome characters amongst the specimens examined. This variation in most instances did not correlate well with host or host status. Spore morphology appeared uniform within a species and spore indices varied only slightly. G. tornatum was found to have a broad host range whereas G. boninense appears to be restricted to palms in Papua New Guinea.

Benefits of fidelity: does host specialization impact nematode parasite life history and fecundity?

PubMed

Koprivnikar, J; Randhawa, H S

2013-04-01

The range of hosts used by a parasite is influenced by macro-evolutionary processes (host switching, host-parasite co-evolution), as well as 'encounter filters' and 'compatibility filters' at the micro-evolutionary level driven by host/parasite ecology and physiology. Host specialization is hypothesized to result in trade-offs with aspects of parasite life history (e.g. reproductive output), but these have not been well studied. We used previously published data to create models examining general relationships among host specificity and important aspects of life history and reproduction for nematodes parasitizing animals. Our results indicate no general trade-off between host specificity and the average pre-patent period (time to first reproduction), female size, egg size, or fecundity of these nematodes. However, female size was positively related to egg size, fecundity, and pre-patent period. Host compatibility may thus not be the primary determinant of specificity in these parasitic nematodes if there are few apparent trade-offs with reproduction, but rather, the encounter opportunities for new host species at the micro-evolutionary level, and other processes at the macro-evolutionary level (i.e. phylogeny). Because host specificity is recognized as a key factor determining the spread of parasitic diseases understanding factors limiting host use are essential to predict future changes in parasite range and occurrence.

The Worm Propagation Model with Dual Dynamic Quarantine Strategy

NASA Astrophysics Data System (ADS)

Yao, Yu; Xie, Xiao-Wu; Guo, Hao; Gao, Fu-Xiang; Yu, Ge

Internet worms are becoming more and more harmful with the rapid development of the Internet. Due to the extremely fast spread and great destructive power of network worms, strong dynamic quarantine strategies are necessary. Inspired by the real-world approach to the prevention and treatment of infectious diseases, this paper proposes a quarantine strategy based on dynamic worm propagation model: the SIQRV dual quarantine model. This strategy uses dynamic quarantine method to make the vulnerable host and infected host quarantined, and then release them after a certain period of time, regardless of whether quarantined host security is checked. Through mathematic modeling, it has been found that when the basic reproduction number R0 is less than a critical value, the system will stabilize in the disease-free equilibrium, that is, in theory, the infected hosts will be completely immune. Finally, by comparing the simulation results and numerical analysis, the basic agreement between the two curves supports the validity of the mathematical model. Our future work will be focusing on taking both the delay and double-quarantine strategy into account and further expanding the scale of our simulation work.

Discovery of novel plant interaction determinants from the genomes of 163 root nodule bacteria

DOE PAGES

Seshadri, Rekha; Reeve, Wayne G.; Ardley, Julie K.; ...

2015-11-20

Root nodule bacteria (RNB) or “rhizobia” are a type of plant growth promoting bacteria, typified by their ability to fix nitrogen for their plant host, fixing nearly 65% of the nitrogen currently utilized in sustainable agricultural production of legume crops and pastures. In this study, we sequenced the genomes of 110 RNB from diverse hosts and biogeographical regions, and undertook a global exploration of all available RNB genera with the aim of identifying novel genetic determinants of symbiotic association and plant growth promotion. Specifically, we performed a subtractive comparative analysis with non-RNB genomes, employed relevant transcriptomic data, and leveraged phylogeneticmore » distribution patterns and sequence signatures based on known precepts of symbioticand host-microbe interactions. A total of 184 protein families were delineated, including known factors for nodulation and nitrogen fixation, and candidates with previously unexplored functions, for which a role in host-interaction, -regulation, biocontrol, and more, could be posited. Lastly, these analyses expand our knowledge of the RNB purview and provide novel targets for strain improvement in the ultimate quest to enhance plant productivity and agricultural sustainability.« less

ChimericSeq: An open-source, user-friendly interface for analyzing NGS data to identify and characterize viral-host chimeric sequences.

PubMed

Shieh, Fwu-Shan; Jongeneel, Patrick; Steffen, Jamin D; Lin, Selena; Jain, Surbhi; Song, Wei; Su, Ying-Hsiu

2017-01-01

Identification of viral integration sites has been important in understanding the pathogenesis and progression of diseases associated with particular viral infections. The advent of next-generation sequencing (NGS) has enabled researchers to understand the impact that viral integration has on the host, such as tumorigenesis. Current computational methods to analyze NGS data of virus-host junction sites have been limited in terms of their accessibility to a broad user base. In this study, we developed a software application (named ChimericSeq), that is the first program of its kind to offer a graphical user interface, compatibility with both Windows and Mac operating systems, and optimized for effectively identifying and annotating virus-host chimeric reads within NGS data. In addition, ChimericSeq's pipeline implements custom filtering to remove artifacts and detect reads with quantitative analytical reporting to provide functional significance to discovered integration sites. The improved accessibility of ChimericSeq through a GUI interface in both Windows and Mac has potential to expand NGS analytical support to a broader spectrum of the scientific community.

ChimericSeq: An open-source, user-friendly interface for analyzing NGS data to identify and characterize viral-host chimeric sequences

PubMed Central

Shieh, Fwu-Shan; Jongeneel, Patrick; Steffen, Jamin D.; Lin, Selena; Jain, Surbhi; Song, Wei

2017-01-01

Identification of viral integration sites has been important in understanding the pathogenesis and progression of diseases associated with particular viral infections. The advent of next-generation sequencing (NGS) has enabled researchers to understand the impact that viral integration has on the host, such as tumorigenesis. Current computational methods to analyze NGS data of virus-host junction sites have been limited in terms of their accessibility to a broad user base. In this study, we developed a software application (named ChimericSeq), that is the first program of its kind to offer a graphical user interface, compatibility with both Windows and Mac operating systems, and optimized for effectively identifying and annotating virus-host chimeric reads within NGS data. In addition, ChimericSeq’s pipeline implements custom filtering to remove artifacts and detect reads with quantitative analytical reporting to provide functional significance to discovered integration sites. The improved accessibility of ChimericSeq through a GUI interface in both Windows and Mac has potential to expand NGS analytical support to a broader spectrum of the scientific community. PMID:28829778

RNA-seq in kinetoplastids: A powerful tool for the understanding of the biology and host-pathogen interactions.

PubMed

Patino, Luz Helena; Ramírez, Juan David

2017-04-01

The kinetoplastids include a large number of parasites responsible for serious diseases in humans and animals (Leishmania and Trypanosoma brucei) considered endemic in several regions of the world. These parasites are characterized by digenetic life cycles that undergo morphological and genetic changes that allow them to adapt to different microenvironments on their vertebrates and invertebrates hosts. Recent advances in ´omics´ technology, specifically transcriptomics have allowed to reveal aspects associated with such molecular changes. So far, different techniques have been used to evaluate the gene expression profile during the various stages of the life cycle of these parasites and during the host-parasite interactions. However, some of them have serious drawbacks that limit the precise study and full understanding of their transcriptomes. Therefore, recently has been implemented the latest technology (RNA-seq), which overcomes the drawbacks of traditional methods. In this review, studies that so far have used RNA-seq are presented and allowed to expand our knowledge regarding the biology of these parasites and their interactions with their hosts. Copyright © 2017 Elsevier B.V. All rights reserved.

Evolution in action: climate change, biodiversity dynamics and emerging infectious disease

PubMed Central

Hoberg, Eric P.; Brooks, Daniel R.

2015-01-01

Climatological variation and ecological perturbation have been pervasive drivers of faunal assembly, structure and diversification for parasites and pathogens through recurrent events of geographical and host colonization at varying spatial and temporal scales of Earth history. Episodic shifts in climate and environmental settings, in conjunction with ecological mechanisms and host switching, are often critical determinants of parasite diversification, a view counter to more than a century of coevolutionary thinking about the nature of complex host–parasite assemblages. Parasites are resource specialists with restricted host ranges, yet shifts onto relatively unrelated hosts are common during phylogenetic diversification of parasite lineages and directly observable in real time. The emerging Stockholm Paradigm resolves this paradox: Ecological Fitting (EF)—phenotypic flexibility and phylogenetic conservatism in traits related to resource use, most notably host preference—provides many opportunities for rapid host switching in changing environments, without the evolution of novel host-utilization capabilities. Host shifts via EF fuel the expansion phase of the Oscillation Hypothesis of host range and speciation and, more generally, the generation of novel combinations of interacting species within the Geographic Mosaic Theory of Coevolution. In synergy, an environmental dynamic of Taxon Pulses establishes an episodic context for host and geographical colonization. PMID:25688014

Frequent conjugative transfer accelerates adaptation of a broad-host-range plasmid to an unfavorable Pseudomonas putida host.

PubMed

Heuer, Holger; Fox, Randal E; Top, Eva M

2007-03-01

IncP-1 plasmids are known to be promiscuous, but it is not understood if they are equally well adapted to various species within their host range. Moreover, little is known about their fate in bacterial communities. We determined if the IncP-1beta plasmid pB10 was unstable in some Proteobacteria, and whether plasmid stability was enhanced after long-term carriage in a single host and when regularly switched between isogenic hosts. Plasmid pB10 was found to be very unstable in Pseudomonas putida H2, and conferred a high cost (c. 20% decrease in fitness relative to the plasmid-free host). H2(pB10) was then evolved under conditions that selected for plasmid maintenance, with or without regular plasmid transfer (host-switching). When tested in the ancestral host, the evolved plasmids were more stable and their cost was significantly reduced (9% and 16% for plasmids from host-switched and nonswitched lineages, respectively). Our findings suggest that IncP-1 plasmids can rapidly adapt to an unfavorable host by improving their overall stability, and that regular conjugative transfer accelerates this process.

Celticecis, a Genus of Gall Midges (Diptera: Cecidomyiidae), Newly Reported for the Western Palearctic Region

Treesearch

Raymond J. Gagné; John C. Moser

1997-01-01

Many Holarctic genera of trees and shrubs are host over much of their ranges to particular genera of Cecidomyiidae. As examples, willows host gall midges of Rabdophaga and Iteomyia, oaks host Macrodiplosis and Polystepha, and birches host Semudobia in both the Nearctic and...

Identification of Mycobacterium avium subsp. hominissuis Isolated From Drinking Water

EPA Science Inventory

Mycobacterium avium (MA) is divided into four subspecies based primarily on host-range and consists of MA subsp. avium (birds), MA subsp. silvaticum (wood pigeons), MA subsp. paratuberculosis (broad, poorly-defined host range), and the recently described MA subsp. hominissuis (hu...

Evasion and Immuno-Endocrine Regulation in Parasite Infection: Two Sides of the Same Coin in Chagas Disease?

PubMed Central

Morrot, Alexandre; Villar, Silvina R.; González, Florencia B.; Pérez, Ana R.

2016-01-01

Chagas disease is a serious illness caused by the protozoan parasite Trypanosoma cruzi. Nearly 30% of chronically infected people develop cardiac, digestive, or mixed alterations, suggesting a broad range of host-parasite interactions that finally impact upon chronic disease outcome. The ability of T. cruzi to persist and cause pathology seems to depend on diverse factors like T. cruzi strains, the infective load and the route of infection, presence of virulence factors, the parasite capacity to avoid protective immune response, the strength and type of host defense mechanisms and the genetic background of the host. The host-parasite interaction is subject to a constant neuro-endocrine regulation that is thought to influence the adaptive immune system, and as the infection proceeds it can lead to a broad range of outcomes, ranging from pathogen elimination to its continued persistence in the host. In this context, T. cruzi evasion strategies and host defense mechanisms can be envisioned as two sides of the same coin, influencing parasite persistence and different outcomes observed in Chagas disease. Understanding how T. cruzi evade host's innate and adaptive immune response will provide important clues to better dissect mechanisms underlying the pathophysiology of Chagas disease. PMID:27242726

Ecology of coliphages in southern California coastal waters.

PubMed

Reyes, V C; Jiang, S C

2010-08-01

This study aims to investigate the ecology of coliphages, an important microbial pollution indicator. Specifically, our experiments address (i) the ability of environmental Escherichia coli (E. coli) to serve as hosts for coliphage replication, and (ii) the temporal and spatial distribution of coliphages in coastal waters. Water samples from three locations in California's Newport Bay watershed were tested for the presence of coliphages every 2 weeks for an entire year. A total of nine E. coli strains isolated from various sources served as hosts for coliphage detection. Coliphage occurrence was significantly different between freshwater, estuarine and coastal locations and correlated with water temperature, salinity and rainfall in the watershed. The coliphages isolated on the environmental hosts had a broad host-range relative to the coliphages isolated on an E. coli strain from sewage and a US EPA recommended strain for coliphage detection. Coliphage occurrence was related to the temperature, rainfall and salinity within the bay. The adaptation to a broad host-range may enable the proliferation of coliphages in the aquatic environment. Understanding the seasonal variation of phages is useful for establishing a background level of coliphage presence in coastal waters. The broad host-range of coliphages isolated on the environmental E. coli host calls for investigation of coliphage replication in the aquatic environment.

Evolution in action: climate change, biodiversity dynamics and emerging infectious disease.

PubMed

Hoberg, Eric P; Brooks, Daniel R

2015-04-05

Climatological variation and ecological perturbation have been pervasive drivers of faunal assembly, structure and diversification for parasites and pathogens through recurrent events of geographical and host colonization at varying spatial and temporal scales of Earth history. Episodic shifts in climate and environmental settings, in conjunction with ecological mechanisms and host switching, are often critical determinants of parasite diversification, a view counter to more than a century of coevolutionary thinking about the nature of complex host-parasite assemblages. Parasites are resource specialists with restricted host ranges, yet shifts onto relatively unrelated hosts are common during phylogenetic diversification of parasite lineages and directly observable in real time. The emerging Stockholm Paradigm resolves this paradox: Ecological Fitting (EF)--phenotypic flexibility and phylogenetic conservatism in traits related to resource use, most notably host preference--provides many opportunities for rapid host switching in changing environments, without the evolution of novel host-utilization capabilities. Host shifts via EF fuel the expansion phase of the Oscillation Hypothesis of host range and speciation and, more generally, the generation of novel combinations of interacting species within the Geographic Mosaic Theory of Coevolution. In synergy, an environmental dynamic of Taxon Pulses establishes an episodic context for host and geographical colonization. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Determinants of host species range in plant viruses.

PubMed

Moury, Benoît; Fabre, Frédéric; Hébrard, Eugénie; Froissart, Rémy

2017-04-01

Prediction of pathogen emergence is an important field of research, both in human health and in agronomy. Most studies of pathogen emergence have focused on the ecological or anthropic factors involved rather than on the role of intrinsic pathogen properties. The capacity of pathogens to infect a large set of host species, i.e. to possess a large host range breadth (HRB), is tightly linked to their emergence propensity. Using an extensive plant virus database, we found that four traits related to virus genome or transmission properties were strongly and robustly linked to virus HRB. Broader host ranges were observed for viruses with single-stranded genomes, those with three genome segments and nematode-transmitted viruses. Also, two contrasted groups of seed-transmitted viruses were evidenced. Those with a single-stranded genome had larger HRB than non-seed-transmitted viruses, whereas those with a double-stranded genome (almost exclusively RNA) had an extremely small HRB. From the plant side, the family taxonomic rank appeared as a critical threshold for virus host range, with a highly significant increase in barriers to infection between plant families. Accordingly, the plant-virus infectivity matrix shows a dual structure pattern: a modular pattern mainly due to viruses specialized to infect plants of a given family and a nested pattern due to generalist viruses. These results contribute to a better prediction of virus host jumps and emergence risks.

Theileria induces oxidative stress and HIF1α activation that are essential for host leukocyte transformation.

PubMed

Medjkane, S; Perichon, M; Marsolier, J; Dairou, J; Weitzman, J B

2014-04-03

Complex links between infection and cancer suggest that we still can learn much about tumorigenesis by studying how infectious agents hijack the host cell machinery. We studied the effects of an intracellular parasite called Theileria that infects bovine leukocytes and turns them into invasive cancer-like cells. We investigated the host cells pathways that are deregulated in infected leukocytes and might link infection and lymphoproliferative disease. We show that intracellular Theileria parasites drive a Warburg-like phenotype in infected host leukocytes, characterized by increased expression of metabolic regulators, increased glucose uptake and elevated lactate production, which were lost when the parasite was eliminated. The cohabitation of the parasites within the host cells leads to disruption of the redox balance (as measured by reduced/oxidized glutathione ratio) and elevated ROS (reactive oxygen species) levels, associated with chronic stabilization of the hypoxia-inducible factor 1 alpha (HIF1α). Inhibition of HIF1α (pharmacologically or genetically), or treatment with antioxidants, led to a marked reduction in expression of aerobic glycolytic genes and inhibited the transformed phenotype. These data show that stabilization of HIF1α, following increased ROS production, modulates host glucose metabolism and is critical for parasite-induced transformation. Our study expands knowledge about the molecular strategy used by the parasite Theileria to induce the transformed phenotypes of infected cells via reprogramming of glucose metabolism and redox signaling.

Two Types of Threonine-Tagged Lipopeptides Synergize in Host Colonization by Pathogenic Burkholderia Species.

PubMed

Thongkongkaew, Tawatchai; Ding, Wei; Bratovanov, Evgeni; Oueis, Emilia; Garcı A-Altares, Marı A; Zaburannyi, Nestor; Harmrolfs, Kirsten; Zhang, Youming; Scherlach, Kirstin; Müller, Rolf; Hertweck, Christian

2018-05-18

Bacterial infections of agriculturally important mushrooms and plants pose a major threat to human food sources worldwide. However, structures of chemical mediators required by the pathogen for host colonization and infection remain elusive in most cases. Here, we report two types of threonine-tagged lipopeptides conserved among mushroom and rice pathogenic Burkholderia species that facilitate bacterial infection of hosts. Genome mining, metabolic profiling of infected mushrooms, and heterologous expression of orphan gene clusters allowed the discovery of these unprecedented metabolites in the mushroom pathogen Burkholderia gladioli (haereogladin, burriogladin) and the plant pathogen Burkholderia glumae (haereoglumin and burrioglumin). Through targeted gene deletions, the molecular basis of lipopeptide biosynthesis by nonribosomal peptide synthetases was revealed. Surprisingly, both types of lipopeptides feature unusual threonine tags, which yield longer peptide backbones than one would expect based on the canonical colinearity of the NRPS assembly lines. Both peptides play an indirect role in host infection as biosurfactants that enable host colonization by mediating swarming and biofilm formation abilities. Moreover, MALDI imaging mass spectrometry was applied to investigate the biological role of the lipopeptides. Our results shed light on conserved mechanisms that mushroom and plant pathogenic bacteria utilize for host infection and expand current knowledge on bacterial virulence factors that may represent a new starting point for the targeted development of crop protection measures in the future.

Host specific glycans are correlated with susceptibility to infection by lagoviruses, but not with their virulence.

PubMed

Lopes, Ana M; Breiman, Adrien; Lora, Mónica; Le Moullac-Vaidye, Béatrice; Galanina, Oxana; Nyström, Kristina; Marchandeau, Stephane; Le Gall-Reculé, Ghislaine; Strive, Tanja; Neimanis, Aleksija; Bovin, Nicolai V; Ruvoën-Clouet, Nathalie; Esteves, Pedro J; Abrantes, Joana; Le Pendu, Jacques

2017-11-29

The rabbit hemorrhagic disease virus (RHDV) and the European brown hare syndrome virus (EBHSV) are two lagoviruses from the family Caliciviridae that cause fatal diseases in two leporid genera, Oryctolagus and Lepus , respectively. In the last few years, several examples of host jumps of lagoviruses among leporids were recorded. In addition, a new pathogenic genotype of RHDV emerged and many non-pathogenic strains of lagoviruses have been described. The molecular mechanisms behind host shifts and the emergence of virulence are unknown. Since RHDV uses glycans of the histo-blood group antigen type as attachment factors to initiate infection, we studied if glycan specificities of the new pathogenic RHDV genotype, non-pathogenic lagoviruses and EBHSV potentially play a role in determining host range and virulence of lagoviruses. We observed binding to A, B or H antigens of the histo-blood group family for all strains known to primarily infect European rabbits ( Oryctolagus cuniculus ), that have recently been classified as GI strains. Yet, we could not explain the emergence of virulence since similar glycan specificities were found between several pathogenic and non-pathogenic strains. By contrast, EBHSV, recently classified as GII.1, bound to terminal β-linked N-acetylglucosamine residues of O-glycans. Expression of these attachment factors in the upper respiratory and digestive tracts in three lagomorph species ( Oryctolagus cuniculus, Lepus europaeus and Sylvilagus floridanus ) showed species-specific patterns regarding the susceptibility to infection by these viruses, indicating that species-specific glycan expression is likely a major contributor to lagoviruses host specificity and range. IMPORTANCE Lagoviruses constitute a genus of the Caliciviridae family, comprising highly pathogenic viruses, RHDV and EBHSV, which infect rabbits and hares, respectively. Recently, non-pathogenic strains were discovered and new pathogenic strains have emerged. In addition, host jumps between lagomorphs are observed. The mechanisms responsible for the emergence of pathogenicity and host-species range are unknown. Previous studies showed that RHDV strains attach to glycans expressed in the upper respiratory and digestive tracts of rabbits, the likely doors of virus entry. Here we studied the glycan-binding properties of novel pathogenic and non-pathogenic strains looking for a link between glycan-binding and virulence or between glycan specificity and host range. We found that glycan binding did not correlate with virulence. However, expression of glycan motifs in the upper respiratory and digestive tracts of lagomorphs revealed species-specific patterns associated with the host range of the virus strains, suggesting that glycan diversity contributes to lagoviruses' host range. Copyright © 2017 American Society for Microbiology.

Novel narrow-host-range vectors for direct cloning of foreign DNA in Pseudomonas.

PubMed

Boivin, R; Bellemare, G; Dion, P

1994-01-01

Narrow-host-range vectors, based on an indigenous replicon and containing a multiple cloning site, have been constructed in a Pseudomonas host capable of growth on unusual substrates. The new cloning vectors yield sufficient amounts of DNA for preparative purposes and belong to an incompatibility group different from that of the incP and incQ broad-host-range vectors. One of these vectors, named pDB47F, was used to clone, directly in Pseudomonas, DNA fragments from Agrobacterium, Pseudomonas, and Rhizobium. A clone containing Agrobacterium and KmR gene sequences was transformed with a higher efficiency than an RSF1010-derived vector (by as much as 1250-fold) in four out of five Pseudomonas strains tested. The considerable efficiency obtained with this system makes possible the direct cloning and phenotypic selection of foreign DNA in Pseudomonas.

The Rheological Properties of Lipid Monolayers Modulate the Incorporation of l-Ascorbic Acid Alkyl Esters.

PubMed

Díaz, Yenisleidy de Las Mercedes Zulueta; Mottola, Milagro; Vico, Raquel V; Wilke, Natalia; Fanani, María Laura

2016-01-19

In this work, we tested the hypothesis that the incorporation of amphiphilic drugs into lipid membranes may be regulated by their rheological properties. For this purpose, two members of the l-ascorbic acid alkyl esters family (ASCn) were selected, ASC16 and ASC14, which have different rheological properties when organized at the air/water interface. They are lipophilic forms of vitamin C used in topical pharmacological preparations. The effect of the phase state of the host lipid membranes on ASCn incorporation was explored using Langmuir monolayers. Films of pure lipids with known phase states have been selected, showing liquid-expanded, liquid-condensed, and solid phases as well as pure cholesterol films in liquid-ordered state. We also tested ternary and quaternary mixed films that mimic the properties of cholesterol containing membranes and of the stratum corneum. The compressibility and shear properties of those monolayers were assessed in order to define its phase character. We found that the length of the acyl chain of the ASCn compounds induces differential changes in the rheological properties of the host membrane and subtly regulates the kinetics and extent of the penetration process. The capacity for ASCn uptake was found to depend on the phase state of the host film. The increase in surface pressure resultant after amphiphile incorporation appears to be a function of the capacity of the host membrane to incorporate such amphiphile as well as the rheological response of the film. Hence, monolayers that show a solid phase state responded with a larger surface pressure increase to the incorporation of a comparable amount of amphiphile than liquid-expanded ones. The cholesterol-containing films, including the mixture that mimics stratum corneum, allowed a very scarce ASCn uptake independently of the membrane diffusional properties. This suggests an important contribution of Cho on the maintenance of the barrier function of stratum corneum.

Genome Expression Profiling-Based Identification and Administration Efficacy of Host-Directed Antimicrobial Drugs against Respiratory Infection by Nontypeable Haemophilus influenzae

PubMed Central

Euba, Begoña; Moleres, Javier; Segura, Víctor; Viadas, Cristina; Morey, Pau; Moranta, David; Leiva, José; de-Torres, Juan Pablo; Bengoechea, José Antonio

2015-01-01

Therapies that are safe, effective, and not vulnerable to developing resistance are highly desirable to counteract bacterial infections. Host-directed therapeutics is an antimicrobial approach alternative to conventional antibiotics based on perturbing host pathways subverted by pathogens during their life cycle by using host-directed drugs. In this study, we identified and evaluated the efficacy of a panel of host-directed drugs against respiratory infection by nontypeable Haemophilus influenzae (NTHi). NTHi is an opportunistic pathogen that is an important cause of exacerbation of chronic obstructive pulmonary disease (COPD). We screened for host genes differentially expressed upon infection by the clinical isolate NTHi375 by analyzing cell whole-genome expression profiling and identified a repertoire of host target candidates that were pharmacologically modulated. Based on the proposed relationship between NTHi intracellular location and persistence, we hypothesized that drugs perturbing host pathways used by NTHi to enter epithelial cells could have antimicrobial potential against NTHi infection. Interfering drugs were tested for their effects on bacterial and cellular viability, on NTHi-epithelial cell interplay, and on mouse pulmonary infection. Glucocorticoids and statins lacked in vitro and/or in vivo efficacy. Conversely, the sirtuin-1 activator resveratrol showed a bactericidal effect against NTHi, and the PDE4 inhibitor rolipram showed therapeutic efficacy by lowering NTHi375 counts intracellularly and in the lungs of infected mice. PDE4 inhibition is currently prescribed in COPD, and resveratrol is an attractive geroprotector for COPD treatment. Together, these results expand our knowledge of NTHi-triggered host subversion and frame the antimicrobial potential of rolipram and resveratrol against NTHi respiratory infection. PMID:26416856

Waste Heat-to-Power Using Scroll Expander for Organic Rankine Bottoming Cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dieckmann, John; Smutzer, Chad; Sinha, Jayanti

The objective of this program was to develop a novel, scalable scroll expander for conversion of waste heat to power; this was accomplished and demonstrated in both a bench-scale system as well as a full-scale system. The expander is a key component in Organic Rankine Cycle (ORC) waste heat recovery systems which are used to convert medium-grade waste heat to electric power in a wide range of industries. These types of waste heat recovery systems allow for the capture of energy that would otherwise just be exhausted to the atmosphere. A scroll expander has the benefit over other technologies ofmore » having high efficiency over a broad range of operating conditions. The speed range of the TIAX expander (1,200 to 3,600 RPM) enables the shaft power output to directly drive an electric generator and produce 60 Hz electric power without incurring the equipment costs or losses of electronic power conversion. This greatly simplifies integration with the plant electric infrastructure. The TIAX scroll expander will reduce the size, cost, and complexity of a small-scale waste heat recovery system, while increasing the system efficiency compared to the prevailing ORC technologies at similar scale. During this project, TIAX demonstrated the scroll expander in a bench-scale test setup to have isentropic efficiency of 70-75% and operated it successfully for ~200 hours with minimal wear. This same expander was then installed in a complete ORC system driven by a medium grade waste heat source to generate 5-7 kW of electrical power. Due to funding constraints, TIAX was unable to complete this phase of testing, although the initial results were promising and demonstrated the potential of the technology.« less

Give It a Shot! Toolkit for Nurses and Other Immunization Champions Working with Secondary Schools. 2nd Edition

ERIC Educational Resources Information Center

Boyer-Chu, Lynda; Wooley, Susan F.

2008-01-01

Adolescent immunization saves lives--but promoting immunization takes time and thought, and today's nurses and other health advocates are faced with a host of ever-expanding responsibilities in a time of reduced budgets and staff. This toolkit is thus structured as an easy and reliable resource. This 2nd edition contains: (1) a 64-page manual;…

Future applications of associative processor systems to operational KSC systems for optimizing cost and enhancing performance characteristics

NASA Technical Reports Server (NTRS)

Perkinson, J. A.

1974-01-01

The application of associative memory processor equipment to conventional host processors type systems is discussed. Efforts were made to demonstrate how such application relieves the task burden of conventional systems, and enhance system speed and efficiency. Data cover comparative theoretical performance analysis, demonstration of expanded growth capabilities, and demonstrations of actual hardware in simulated environment.

Host specificity and the probability of discovering species of helminth parasites.

PubMed

Poulin, R; Mouillot, D

2005-06-01

Different animal species have different probabilities of being discovered and described by scientists, and these probabilities are determined to a large extent by the biological characteristics of these species. For instance, species with broader geographical ranges are more likely to be encountered by collectors than species with restricted distributions; indeed, the size of the geographical range is often the best predictor of a species' date of description. For parasitic organisms, host specificity may be similarly linked to the probability of a species being found. Here, using data on 170 helminth species parasitic in freshwater fishes, we show that host specificity is associated with the year in which the helminths were described. Helminths that exploit more host species, and to a lesser degree those that exploit a broader taxonomic range of host species, tend to be discovered earlier than the more host-specific helminths. This pattern was observed across all helminth species, as well as within the different helminth taxa (trematodes, cestodes, nematodes and acanthocephalans). Our results demonstrate that the parasite species known at any given point in time are not a random subset of existing species, but rather a biased subset with respect to the parasites' biological properties.

Characterization of Arabidopsis Transcriptional Responses to Different Aphid Species Reveals Genes that Contribute to Host Susceptibility and Non-host Resistance

PubMed Central

Jaouannet, Maëlle; Morris, Jenny A.; Hedley, Peter E.; Bos, Jorunn I. B.

2015-01-01

Aphids are economically important pests that display exceptional variation in host range. The determinants of diverse aphid host ranges are not well understood, but it is likely that molecular interactions are involved. With significant progress being made towards understanding host responses upon aphid attack, the mechanisms underlying non-host resistance remain to be elucidated. Here, we investigated and compared Arabidopsis thaliana host and non-host responses to aphids at the transcriptional level using three different aphid species, Myzus persicae, Myzus cerasi and Rhopalosiphum pisum. Gene expression analyses revealed a high level of overlap in the overall gene expression changes during the host and non-host interactions with regards to the sets of genes differentially expressed and the direction of expression changes. Despite this overlap in transcriptional responses across interactions, there was a stronger repression of genes involved in metabolism and oxidative responses specifically during the host interaction with M. persicae. In addition, we identified a set of genes with opposite gene expression patterns during the host versus non-host interactions. Aphid performance assays on Arabidopsis mutants that were selected based on our transcriptome analyses identified novel genes contributing to host susceptibility, host defences during interactions with M. persicae as well to non-host resistance against R. padi. Understanding how plants respond to aphid species that differ in their ability to infest plant species, and identifying the genes and signaling pathways involved, is essential for the development of novel and durable aphid control in crop plants. PMID:25993686

Global and comparative proteomic profiling of overwintering and developing mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae), larvae.

PubMed

Bonnett, Tiffany R; Robert, Jeanne A; Pitt, Caitlin; Fraser, Jordie D; Keeling, Christopher I; Bohlmann, Jörg; Huber, Dezene P W

2012-12-01

Mountain pine beetles, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), are native to western North America, but have recently begun to expand their range across the Canadian Rocky Mountains. The requirement for larvae to withstand extremely cold winter temperatures and potentially toxic host secondary metabolites in the midst of their ongoing development makes this a critical period of their lives. We have uncovered global protein profiles for overwintering mountain pine beetle larvae. We have also quantitatively compared the proteomes for overwintering larvae sampled during autumn cooling and spring warming using iTRAQ methods. We identified 1507 unique proteins across all samples. In total, 33 proteins exhibited differential expression (FDR < 0.05) when compared between larvae before and after a cold snap in the autumn; and 473 proteins exhibited differential expression in the spring when measured before and after a steady incline in mean daily temperature. Eighteen proteins showed significant changes in both autumn and spring samples. These first proteomic data for mountain pine beetle larvae show evidence of the involvement of trehalose, 2-deoxyglucose, and antioxidant enzymes in overwintering physiology; confirm and expand upon previous work implicating glycerol in cold tolerance in this insect; and provide new, detailed information on developmental processes in beetles. These results and associated data will be an invaluable resource for future targeted research on cold tolerance mechanisms in the mountain pine beetle and developmental biology in coleopterans. Copyright © 2012 Elsevier Ltd. All rights reserved.

Translation efficiency of heterologous proteins is significantly affected by the genetic context of RBS sequences in engineered cyanobacterium Synechocystis sp. PCC 6803.

PubMed

Thiel, Kati; Mulaku, Edita; Dandapani, Hariharan; Nagy, Csaba; Aro, Eva-Mari; Kallio, Pauli

2018-03-02

Photosynthetic cyanobacteria have been studied as potential host organisms for direct solar-driven production of different carbon-based chemicals from CO 2 and water, as part of the development of sustainable future biotechnological applications. The engineering approaches, however, are still limited by the lack of comprehensive information on most optimal expression strategies and validated species-specific genetic elements which are essential for increasing the intricacy, predictability and efficiency of the systems. This study focused on the systematic evaluation of the key translational control elements, ribosome binding sites (RBS), in the cyanobacterial host Synechocystis sp. PCC 6803, with the objective of expanding the palette of tools for more rigorous engineering approaches. An expression system was established for the comparison of 13 selected RBS sequences in Synechocystis, using several alternative reporter proteins (sYFP2, codon-optimized GFPmut3 and ethylene forming enzyme) as quantitative indicators of the relative translation efficiencies. The set-up was shown to yield highly reproducible expression patterns in independent analytical series with low variation between biological replicates, thus allowing statistical comparison of the activities of the different RBSs in vivo. While the RBSs covered a relatively broad overall expression level range, the downstream gene sequence was demonstrated in a rigorous manner to have a clear impact on the resulting translational profiles. This was expected to reflect interfering sequence-specific mRNA-level interaction between the RBS and the coding region, yet correlation between potential secondary structure formation and observed translation levels could not be resolved with existing in silico prediction tools. The study expands our current understanding on the potential and limitations associated with the regulation of protein expression at translational level in engineered cyanobacteria. The acquired information can be used for selecting appropriate RBSs for optimizing over-expression constructs or multicistronic pathways in Synechocystis, while underlining the complications in predicting the activity due to gene-specific interactions which may reduce the translational efficiency for a given RBS-gene combination. Ultimately, the findings emphasize the need for additional characterized insulator sequence elements to decouple the interaction between the RBS and the coding region for future engineering approaches.

Coronavirus and paramyxovirus in bats from Northwest Italy.

PubMed

Rizzo, Francesca; Edenborough, Kathryn M; Toffoli, Roberto; Culasso, Paola; Zoppi, Simona; Dondo, Alessandro; Robetto, Serena; Rosati, Sergio; Lander, Angelika; Kurth, Andreas; Orusa, Riccardo; Bertolotti, Luigi; Mandola, Maria Lucia

2017-12-22

Bat-borne virus surveillance is necessary for determining inter-species transmission risks and is important due to the wide-range of bat species which may harbour potential pathogens. This study aimed to monitor coronaviruses (CoVs) and paramyxoviruses (PMVs) in bats roosting in northwest Italian regions. Our investigation was focused on CoVs and PMVs due to their proven ability to switch host and their zoonotic potential. Here we provide the phylogenetic characterization of the highly conserved polymerase gene fragments. Family-wide PCR screenings were used to test 302 bats belonging to 19 different bat species. Thirty-eight animals from 12 locations were confirmed as PCR positive, with an overall detection rate of 12.6% [95% CI: 9.3-16.8]. CoV RNA was found in 36 bats belonging to eight species, while PMV RNA in three Pipistrellus spp. Phylogenetic characterization have been obtained for 15 alpha- CoVs, 5 beta-CoVs and three PMVs; moreover one P. pipistrellus resulted co-infected with both CoV and PMV. A divergent alpha-CoV clade from Myotis nattereri SpA is also described. The compact cluster of beta-CoVs from R. ferrumequinum roosts expands the current viral sequence database, specifically for this species in Europe. To our knowledge this is the first report of CoVs in Plecotus auritus and M. oxygnathus, and of PMVs in P. kuhlii. This study identified alpha and beta-CoVs in new bat species and in previously unsurveyed Italian regions. To our knowledge this represents the first and unique report of PMVs in Italy. The 23 new bat genetic sequences presented will expand the current molecular bat-borne virus databases. Considering the amount of novel bat-borne PMVs associated with the emergence of zoonotic infections in animals and humans in the last years, the definition of viral diversity within European bat species is needed. Performing surveillance studies within a specific geographic area can provide awareness of viral burden where bats roost in close proximity to spillover hosts, and form the basis for the appropriate control measures against potential threats for public health and optimal management of bats and their habitats.

Identification of the same polyomavirus species in different African horseshoe bat species is indicative of short-range host-switching events.

PubMed

Carr, Michael; Gonzalez, Gabriel; Sasaki, Michihito; Dool, Serena E; Ito, Kimihito; Ishii, Akihiro; Hang'ombe, Bernard M; Mweene, Aaron S; Teeling, Emma C; Hall, William W; Orba, Yasuko; Sawa, Hirofumi

2017-10-06

Polyomaviruses (PyVs) are considered to be highly host-specific in different mammalian species, with no well-supported evidence for host-switching events. We examined the species diversity and host specificity of PyVs in horseshoe bats (Rhinolophus spp.), a broadly distributed and highly speciose mammalian genus. We annotated six PyV genomes, comprising four new PyV species, based on pairwise identity within the large T antigen (LTAg) coding region. Phylogenetic comparisons revealed two instances of highly related PyV species, one in each of the Alphapolyomavirus and Betapolyomavirus genera, present in different horseshoe bat host species (Rhinolophus blasii and R. simulator), suggestive of short-range host-switching events. The two pairs of Rhinolophus PyVs in different horseshoe bat host species were 99.9 and 88.8 % identical with each other over their respective LTAg coding sequences and thus constitute the same virus species. To corroborate the species identification of the bat hosts, we analysed mitochondrial cytb and a large nuclear intron dataset derived from six independent and neutrally evolving loci for bat taxa of interest. Bayesian estimates of the ages of the most recent common ancestors suggested that the near-identical and more distantly related PyV species diverged approximately 9.1E4 (5E3-2.8E5) and 9.9E6 (4E6-18E6) years before the present, respectively, in contrast to the divergence times of the bat host species: 12.4E6 (10.4E6-15.4E6). Our findings provide evidence that short-range host-switching of PyVs is possible in horseshoe bats, suggesting that PyV transmission between closely related mammalian species can occur.

Species turnover drives β-diversity patterns across multiple spatial scales of plant-galling interactions in mountaintop grasslands.

PubMed

Coelho, Marcel Serra; Carneiro, Marco Antônio Alves; Branco, Cristina Alves; Borges, Rafael Augusto Xavier; Fernandes, Geraldo Wilson

2018-01-01

This study describes differences in species richness and composition of the assemblages of galling insects and their host plants at different spatial scales. Sampling was conducted along altitudinal gradients composed of campos rupestres and campos de altitude of two mountain complexes in southeastern Brazil: Espinhaço Range and Mantiqueira Range. The following hypotheses were tested: i) local and regional richness of host plants and galling insects are positively correlated; ii) beta diversity is the most important component of regional diversity of host plants and galling insects; and iii) Turnover is the main mechanism driving beta diversity of both host plants and galling insects. Local richness of galling insects and host plants increased with increasing regional richness of species, suggesting a pattern of unsaturated communities. The additive partition of regional richness (γ) into local and beta components shows that local richnesses (α) of species of galling insects and host plants are low relative to regional richness; the beta (β) component incorporates most of the regional richness. The multi-scale analysis of additive partitioning showed similar patterns for galling insects and host plants with the local component (α) incorporated a small part of regional richness. Beta diversity of galling insects and host plants were mainly the result of turnover, with little contribution from nesting. Although the species composition of galling insects and host plant species varied among sample sites, mountains and even mountain ranges, local richness remained relatively low. In this way, the addition of local habitats with different landscapes substantially affects regional richness. Each mountain contributes fundamentally to the composition of regional diversity of galling insects and host plants, and so the design of future conservation strategies should incorporate multiple scales.

The Frequency of Fitness Peak Shifts Is Increased at Expanding Range Margins Due to Mutation Surfing

PubMed Central

Burton, Olivia J.; Travis, Justin M. J.

2008-01-01

Dynamic species' ranges, those that are either invasive or shifting in response to environmental change, are the focus of much recent interest in ecology, evolution, and genetics. Understanding how range expansions can shape evolutionary trajectories requires the consideration of nonneutral variability and genetic architecture, yet the majority of empirical and theoretical work to date has explored patterns of neutral variability. Here we use forward computer simulations of population growth, dispersal, and mutation to explore how range-shifting dynamics can influence evolution on rugged fitness landscapes. We employ a two-locus model, incorporating sign epistasis, and find that there is an increased likelihood of fitness peak shifts during a period of range expansion. Maladapted valley genotypes can accumulate at an expanding range front through a phenomenon called mutation surfing, which increases the likelihood that a mutation leading to a higher peak will occur. Our results indicate that most peak shifts occur close to the expanding front. We also demonstrate that periods of range shifting are especially important for peak shifting in species with narrow geographic distributions. Our results imply that trajectories on rugged fitness landscapes can be modified substantially when ranges are dynamic. PMID:18505864

Fine Structure of Bacteroids in Root Nodules of Vigna sinensis, Acacia longifolia, Viminaria juncea, and Lupinus angustifolius

PubMed Central

Dart, P. J.; Mercer, F. V.

1966-01-01

Dart, P. J. (University of Sydney, Sydney, Australia), and F. V. Mercer. Fine structure of bacteroids in root nodules of Vigna sinensis, Acacia longifolia, Viminaria juncea, and Lupinus angustifolius. J. Bacteriol. 91:1314–1319.—In nodules of Vigna sinensis, Acacia longifolia, and Viminaria juncea, membrane envelopes enclose groups of bacteroids. The bacteroids often contain inclusion granules and electron-dense bodies, expand little during development, and retain their rod form with a compact, central nucleoid area. The membrane envelope may persist around bacteroids after host cytoplasm breakdown. In nodules of Lupinus angustifolius, the membrane envelopes enclose only one or two bacteroids, which expand noticeably during development and change from their initial rod structure. Images PMID:5929757

Host Fish Identification and Early Life Thermal Requirements for the Federal Endangered Winged Mapleleaf Mussel

USGS Publications Warehouse

Steingraeber, Mark; Newton, Teresa J.

2005-01-01

The winged mapleleaf mussel (Quadrula fragosa, WML) is a Federal endangered species historically inhabiting at least 34 river systems in 12 Midwestern states. Only four populations are currently known to exist, including one confirmed reproducing population in the St. Croix National Scenic Riverway (NSR) bordering Minnesota and Wisconsin. Recovery efforts are limited by a lack of life history information, particularly which species of fish serve as host to the mussel's parasitic larvae (glochidia). Since 1997, biologists at the University of Minnesota have tried to identify host fish for the WML. Department of the Interior colleagues working in western Wisconsin at the U.S. Fish and Wildlife Service's La Crosse Fishery Resources Office and Genoa National Fish Hatchery, the National Park Service's St. Croix NSR, and the U.S. Geological Survey's Upper Midwest Environmental Sciences Center (UMESC) in La Crosse joined the team in 2001 to expand and accelerate the laboratory host fish identification program by making use of the well-equipped aquatic research facilities at UMESC. We report on several WML early life history investigations conducted at UMESC since autumn 2003 to identify suitable host fish species and evaluate thermal requisites for the development of glochidia into free-living juvenile mussels.

Systems Biology Approaches for Host–Fungal Interactions: An Expanding Multi-Omics Frontier

PubMed Central

Culibrk, Luka; Croft, Carys A.

2016-01-01

Abstract Opportunistic fungal infections are an increasing threat for global health, and for immunocompromised patients in particular. These infections are characterized by interaction between fungal pathogen and host cells. The exact mechanisms and the attendant variability in host and fungal pathogen interaction remain to be fully elucidated. The field of systems biology aims to characterize a biological system, and utilize this knowledge to predict the system's response to stimuli such as fungal exposures. A multi-omics approach, for example, combining data from genomics, proteomics, metabolomics, would allow a more comprehensive and pan-optic “two systems” biology of both the host and the fungal pathogen. In this review and literature analysis, we present highly specialized and nascent methods for analysis of multiple -omes of biological systems, in addition to emerging single-molecule visualization techniques that may assist in determining biological relevance of multi-omics data. We provide an overview of computational methods for modeling of gene regulatory networks, including some that have been applied towards the study of an interacting host and pathogen. In sum, comprehensive characterizations of host–fungal pathogen systems are now possible, and utilization of these cutting-edge multi-omics strategies may yield advances in better understanding of both host biology and fungal pathogens at a systems scale. PMID:26885725

Chromospheric and Transition Region Emission Properties of G, K, and M dwarf Exoplanet Host Stars

NASA Astrophysics Data System (ADS)

France, Kevin; Arulanantham, Nicole; Fossati, Luca; Lanza, A. F.; Linsky, Jeffrey L.; Redfield, Seth; Loyd, Robert; Schneider, Christian

2018-01-01

Exoplanet magnetic fields have proven notoriously hard to detect, despite theoretical predictions of substantial magnetic field strengths on close-in extrasolar giant planets. It has been suggested that stellar and planetary magnetic field interactions can manifest as enhanced stellar activity relative to nominal age-rotation-activity relationships for main sequence stars or enhanced activity on stars hosting short-period massive planets. In a recent study of M and K dwarf exoplanet host stars, we demonstrated a significant correlation between the relative luminosity in high-temperature stellar emission lines (L(ion)/L_Bol) and the “star-planet interaction strength”, M_plan/a_plan. Here, we expand on that work with a survey of G, K, and M dwarf exoplanet host stars obtained in two recent far-ultraviolet spectroscopic programs with the Hubble Space Telescope. We have measured the relative luminosities of stellar lines C II, Si III, Si IV, and N V (formation temperatures from 30,000 – 150,000 K) in a sample of ~60 exoplanet host stars and an additional ~40 dwarf stars without known planets. We present results on star-planet interaction signals as a function of spectral type and line formation temperature, as well as a statistical comparison of stars with and without planets.

Expanding the vision of the Experimental Forest and Range network to urban areas

Treesearch

J. Morgan Grove

2014-01-01

After 100 years, the USDA Forest Service has emerging opportunities to expand the Experimental Forest and Range (EFR) network to urban areas. The purpose of this expansion would be to broaden the types of ecosystems studied, interdisciplinary approaches used, and relevance to society of the EFR network through long-term and large-scale social-ecological projects in...

Expanding the Education Universe: A Fifty-State Strategy for Course Choice

ERIC Educational Resources Information Center

Brickman, Michael

2014-01-01

After twenty years of expanding school-choice options, state leaders, educators, and families have a new tool: course choice, a strategy for students to learn from unconventional providers that might range from top-tier universities or innovative community colleges to local employers, labs, or hospitals. In "Expanding the Education Universe:…

Finalizing host range determination of a weed biological control pathogen with BLUPs and damage assessment

USDA-ARS?s Scientific Manuscript database

Colletotrichum gloeosporioides f. sp. salsolae (Penz.) Penz. & Sacc. in Penz. (CGS) is a facultative parasitic fungus being evaluated as a classical biological control agent of Russian thistle or tumbleweed (Salsola tragus L.). In initial host range determination tests, Henderson’s mixed model equat...

Fundamental host range of Leptoypha hospita (Hemiptera: Tingidae), a potential biological control agent of Chinese privet

Treesearch

Yanzhuo Zhang; James L. Hanula; Scott Horn; Cera Jones; S. Kristine Braman; Jianghua Sun

2016-01-01

Chinese privet, Ligustrum sinense Lour., is an invasive shrub within riparian areas of the southeastern United States. Biological control is considered the most suitable management option for Chinese privet. The potential host range of the lace bug, Leptoypha hospita Drake et...

Lack of Host Specialization on Winter Annual Grasses in the Fungal Seed Bank Pathogen Pyrenophora semeniperda

PubMed Central

Beckstead, Julie; Meyer, Susan E.; Ishizuka, Toby S.; McEvoy, Kelsey M.; Coleman, Craig E.

2016-01-01

Generalist plant pathogens may have wide host ranges, but many exhibit varying degrees of host specialization, with multiple pathogen races that have narrower host ranges. These races are often genetically distinct, with each race causing highest disease incidence on its host of origin. We examined host specialization in the seed pathogen Pyrenophora semeniperda by reciprocally inoculating pathogen strains from Bromus tectorum and from four other winter annual grass weeds (Bromus diandrus, Bromus rubens, Bromus arvensis and Taeniatherum caput-medusae) onto dormant seeds of B. tectorum and each alternate host. We found that host species varied in resistance and pathogen strains varied in aggressiveness, but there was no evidence for host specialization. Most variation in aggressiveness was among strains within populations and was expressed similarly on both hosts, resulting in a positive correlation between strain-level disease incidence on B. tectorum and on the alternate host. In spite of this lack of host specialization, we detected weak but significant population genetic structure as a function of host species using two neutral marker systems that yielded similar results. This genetic structure is most likely due to founder effects, as the pathogen is known to be dispersed with host seeds. All host species were highly susceptible to their own pathogen races. Tolerance to infection (i.e., the ability to germinate even when infected and thereby avoid seed mortality) increased as a function of seed germination rate, which in turn increased as dormancy was lost. Pyrenophora semeniperda apparently does not require host specialization to fully exploit these winter annual grass species, which share many life history features that make them ideal hosts for this pathogen. PMID:26950931

Molecular basis of recognition between phytophthora pathogens and their hosts.

PubMed

Tyler, Brett M

2002-01-01

Recognition is the earliest step in any direct plant-microbe interaction. Recognition between Phytophthora pathogens, which are oomycetes, phylogenetically distinct from fungi, has been studied at two levels. Recognition of the host by the pathogen has focused on recognition of chemical, electrical, and physical features of plant roots by zoospores. Both host-specific factors such as isoflavones, and host-nonspecific factors such as amino acids, calcium, and electrical fields, influence zoospore taxis, encystment, cyst germination, and hyphal chemotropism in guiding the pathogen to potential infection sites. Recognition of the pathogen by the host defense machinery has been analyzed using biochemical and genetic approaches. Biochemical approaches have identified chemical elicitors of host defense responses, and in some cases, their cognate receptors from the host. Some elicitors, such as glucans and fatty acids, have broad host ranges, whereas others such as elicitins have narrow host ranges. Most elicitors identified appear to contribute primarily to basic or nonhost resistance. Genetic analysis has identified host resistance (R) genes and pathogen avirulence (Avr) genes that interact in a gene-for-gene manner. One Phytophthora Avr gene, Avr1b from P. sojae, has been cloned and characterized. It encodes a secreted elicitor that triggers a system-wide defense response in soybean plants carrying the cognate R gene, Rps1b.

Yersinia enterocolitica-Specific Infection by Bacteriophages TG1 and ϕR1-RT Is Dependent on Temperature-Regulated Expression of the Phage Host Receptor OmpF.

PubMed

Leon-Velarde, Carlos G; Happonen, Lotta; Pajunen, Maria; Leskinen, Katarzyna; Kropinski, Andrew M; Mattinen, Laura; Rajtor, Monika; Zur, Joanna; Smith, Darren; Chen, Shu; Nawaz, Ayesha; Johnson, Roger P; Odumeru, Joseph A; Griffiths, Mansel W; Skurnik, Mikael

2016-09-01

Bacteriophages present huge potential both as a resource for developing novel tools for bacterial diagnostics and for use in phage therapy. This potential is also valid for bacteriophages specific for Yersinia enterocolitica To increase our knowledge of Y. enterocolitica-specific phages, we characterized two novel yersiniophages. The genomes of the bacteriophages vB_YenM_TG1 (TG1) and vB_YenM_ϕR1-RT (ϕR1-RT), isolated from pig manure in Canada and from sewage in Finland, consist of linear double-stranded DNA of 162,101 and 168,809 bp, respectively. Their genomes comprise 262 putative coding sequences and 4 tRNA genes and share 91% overall nucleotide identity. Based on phylogenetic analyses of their whole-genome sequences and large terminase subunit protein sequences, a genus named Tg1virus within the family Myoviridae is proposed, with TG1 and ϕR1-RT (R1RT in the ICTV database) as member species. These bacteriophages exhibit a host range restricted to Y. enterocolitica and display lytic activity against the epidemiologically significant serotypes O:3, O:5,27, and O:9 at and below 25°C. Adsorption analyses of lipopolysaccharide (LPS) and OmpF mutants demonstrate that these phages use both the LPS inner core heptosyl residues and the outer membrane protein OmpF as phage receptors. Based on RNA sequencing and quantitative proteomics, we also demonstrate that temperature-dependent infection is due to strong repression of OmpF at 37°C. In addition, ϕR1-RT was shown to be able to enter into a pseudolysogenic state. Together, this work provides further insight into phage-host cell interactions by highlighting the importance of understanding underlying factors which may affect the abundance of phage host receptors on the cell surface. Only a small number of bacteriophages infecting Y. enterocolitica, the predominant causative agent of yersiniosis, have been previously described. Here, two newly isolated Y. enterocolitica phages were studied in detail, with the aim of elucidating the host cell receptors required for infection. Our research further expands the repertoire of phages available for consideration as potential antimicrobial agents or as diagnostic tools for this important bacterial pathogen. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Yersinia enterocolitica-Specific Infection by Bacteriophages TG1 and ϕR1-RT Is Dependent on Temperature-Regulated Expression of the Phage Host Receptor OmpF

PubMed Central

Happonen, Lotta; Pajunen, Maria; Leskinen, Katarzyna; Kropinski, Andrew M.; Mattinen, Laura; Rajtor, Monika; Zur, Joanna; Smith, Darren; Chen, Shu; Nawaz, Ayesha; Johnson, Roger P.; Odumeru, Joseph A.; Griffiths, Mansel W.

2016-01-01

ABSTRACT Bacteriophages present huge potential both as a resource for developing novel tools for bacterial diagnostics and for use in phage therapy. This potential is also valid for bacteriophages specific for Yersinia enterocolitica. To increase our knowledge of Y. enterocolitica-specific phages, we characterized two novel yersiniophages. The genomes of the bacteriophages vB_YenM_TG1 (TG1) and vB_YenM_ϕR1-RT (ϕR1-RT), isolated from pig manure in Canada and from sewage in Finland, consist of linear double-stranded DNA of 162,101 and 168,809 bp, respectively. Their genomes comprise 262 putative coding sequences and 4 tRNA genes and share 91% overall nucleotide identity. Based on phylogenetic analyses of their whole-genome sequences and large terminase subunit protein sequences, a genus named Tg1virus within the family Myoviridae is proposed, with TG1 and ϕR1-RT (R1RT in the ICTV database) as member species. These bacteriophages exhibit a host range restricted to Y. enterocolitica and display lytic activity against the epidemiologically significant serotypes O:3, O:5,27, and O:9 at and below 25°C. Adsorption analyses of lipopolysaccharide (LPS) and OmpF mutants demonstrate that these phages use both the LPS inner core heptosyl residues and the outer membrane protein OmpF as phage receptors. Based on RNA sequencing and quantitative proteomics, we also demonstrate that temperature-dependent infection is due to strong repression of OmpF at 37°C. In addition, ϕR1-RT was shown to be able to enter into a pseudolysogenic state. Together, this work provides further insight into phage-host cell interactions by highlighting the importance of understanding underlying factors which may affect the abundance of phage host receptors on the cell surface. IMPORTANCE Only a small number of bacteriophages infecting Y. enterocolitica, the predominant causative agent of yersiniosis, have been previously described. Here, two newly isolated Y. enterocolitica phages were studied in detail, with the aim of elucidating the host cell receptors required for infection. Our research further expands the repertoire of phages available for consideration as potential antimicrobial agents or as diagnostic tools for this important bacterial pathogen. PMID:27342557

Life in a rock pool: Radiation and population genetics of myxozoan parasites in hosts inhabiting restricted spaces.

PubMed

Bartošová-Sojková, Pavla; Lövy, Alena; Reed, Cecile C; Lisnerová, Martina; Tomková, Tereza; Holzer, Astrid S; Fiala, Ivan

2018-01-01

Intertidal rock pools where fish and invertebrates are in constant close contact due to limited space and water level fluctuations represent ideal conditions to promote life cycles in parasites using these two alternate hosts and to study speciation processes that could contribute to understanding the roles of parasitic species in such ecosystems. Gall bladder and liver samples from five clinid fish species (Blenniiformes: Clinidae) were morphologically and molecularly examined to determine the diversity, prevalence, distribution and host specificity of Ceratomyxa parasites (Cnidaria: Myxozoa) in intertidal habitats along the coast of South Africa. Phylogenetic relationships of clinid ceratomyxids based on the SSU rDNA, LSU rDNA and ITS regions were assessed additionally to the investigation of population genetic structure of Ceratomyxa cottoidii and subsequent comparison with the data known from type fish host Clinus cottoides. Seven Ceratomyxa species including previously described Ceratomyxa dehoopi and C. cottoidii were recognized in clinids. They represent a diverse group of rapidly evolving, closely related species with a remarkably high prevalence in their hosts, little host specificity and frequent concurrent infections, most probably as a result of parasite radiation after multiple speciation events triggered by limited host dispersal within restricted spaces. C. cottoidii represents the most common clinid parasite with a population structure characterized by young expanding populations in the south west and south east coast and by older populations in equilibrium on the west coast of its distribution. Parasite and fish host population structures show overlapping patterns and are very likely affected by similar oceanographic barriers possibly due to reduced host dispersal enhancing parasite community differentiation. While fish host specificity had little impact on parasite population structure, the habitat preference of the alternate invertebrate host as well as tidal water exchange may be additional crucial variables affecting the dispersal and associated population structure of C. cottoidii.

Life in a rock pool: Radiation and population genetics of myxozoan parasites in hosts inhabiting restricted spaces

PubMed Central

Reed, Cecile C.; Lisnerová, Martina; Tomková, Tereza; Holzer, Astrid S.; Fiala, Ivan

2018-01-01

Introduction Intertidal rock pools where fish and invertebrates are in constant close contact due to limited space and water level fluctuations represent ideal conditions to promote life cycles in parasites using these two alternate hosts and to study speciation processes that could contribute to understanding the roles of parasitic species in such ecosystems. Material and methods Gall bladder and liver samples from five clinid fish species (Blenniiformes: Clinidae) were morphologically and molecularly examined to determine the diversity, prevalence, distribution and host specificity of Ceratomyxa parasites (Cnidaria: Myxozoa) in intertidal habitats along the coast of South Africa. Phylogenetic relationships of clinid ceratomyxids based on the SSU rDNA, LSU rDNA and ITS regions were assessed additionally to the investigation of population genetic structure of Ceratomyxa cottoidii and subsequent comparison with the data known from type fish host Clinus cottoides. Results and discussion Seven Ceratomyxa species including previously described Ceratomyxa dehoopi and C. cottoidii were recognized in clinids. They represent a diverse group of rapidly evolving, closely related species with a remarkably high prevalence in their hosts, little host specificity and frequent concurrent infections, most probably as a result of parasite radiation after multiple speciation events triggered by limited host dispersal within restricted spaces. C. cottoidii represents the most common clinid parasite with a population structure characterized by young expanding populations in the south west and south east coast and by older populations in equilibrium on the west coast of its distribution. Parasite and fish host population structures show overlapping patterns and are very likely affected by similar oceanographic barriers possibly due to reduced host dispersal enhancing parasite community differentiation. While fish host specificity had little impact on parasite population structure, the habitat preference of the alternate invertebrate host as well as tidal water exchange may be additional crucial variables affecting the dispersal and associated population structure of C. cottoidii. PMID:29561884

Quantifying Heterogeneity in Host-Vector Contact: Tsetse (Glossina swynnertoni and G. pallidipes) Host Choice in Serengeti National Park, Tanzania

PubMed Central

Auty, Harriet; Cleaveland, Sarah; Malele, Imna; Masoy, Joseph; Lembo, Tiziana; Bessell, Paul; Torr, Stephen; Picozzi, Kim; Welburn, Susan C.

2016-01-01

Background Identifying hosts of blood-feeding insect vectors is crucial in understanding their role in disease transmission. Rhodesian human African trypanosomiasis (rHAT), also known as acute sleeping sickness is caused by Trypanosoma brucei rhodesiense and transmitted by tsetse flies. The disease is commonly associated with wilderness areas of east and southern Africa. Such areas hold a diverse range of species which form communities of hosts for disease maintenance. The relative importance of different wildlife hosts remains unclear. This study quantified tsetse feeding preferences in a wilderness area of great host species richness, Serengeti National Park, Tanzania, assessing tsetse feeding and host density contemporaneously. Methods Glossina swynnertoni and G. pallidipes were collected from six study sites. Bloodmeal sources were identified through matching Cytochrome B sequences amplified from bloodmeals from recently fed flies to published sequences. Densities of large mammal species in each site were quantified, and feeding indices calculated to assess the relative selection or avoidance of each host species by tsetse. Results The host species most commonly identified in G. swynnertoni bloodmeals, warthog (94/220), buffalo (48/220) and giraffe (46/220), were found at relatively low densities (3-11/km2) and fed on up to 15 times more frequently than expected by their relative density. Wildebeest, zebra, impala and Thomson’s gazelle, found at the highest densities, were never identified in bloodmeals. Commonly identified hosts for G. pallidipes were buffalo (26/46), giraffe (9/46) and elephant (5/46). Conclusions This study is the first to quantify tsetse host range by molecular analysis of tsetse diet with simultaneous assessment of host density in a wilderness area. Although G. swynnertoni and G. pallidipes can feed on a range of species, they are highly selective. Many host species are rarely fed on, despite being present in areas where tsetse are abundant. These feeding patterns, along with the ability of key host species to maintain and transmit T. b. rhodesiense, drive the epidemiology of rHAT in wilderness areas. PMID:27706167

Unravelling the role of host plant expansion in the diversification of a Neotropical butterfly genus.

PubMed

McClure, Melanie; Elias, Marianne

2016-06-16

Understanding the processes underlying diversification is a central question in evolutionary biology. For butterflies, access to new host plants provides opportunities for adaptive speciation. On the one hand, locally abundant host species can generate ecologically significant selection pressure. But a diversity of host plant species within the geographic range of each population and/or species might also eliminate any advantage conferred by specialization. This paper focuses on four Melinaea species, which are oligophagous on the family Solanaceae: M. menophilus, M. satevis, M. marsaeus, and finally, M. mothone. We examined both female preference and larval performance on two host plant species that commonly occur in this butterfly's native range, Juanulloa parasitica and Trianaea speciosa, to determine whether the different Melinaea species show evidence of local adaptation. In choice experiments, M. mothone females used both host plants for oviposition, whereas all other species used J. parasitica almost exclusively. In no choice experiment, M. mothone was the only species that readily accepted T. speciosa as a larval host plant. Larval survival was highest on J. parasitica (82.0 % vs. 60.9 %) and development took longer on T. speciosa (14.12 days vs. 13.35 days), except for M. mothone, which did equally well on both host plants. For all species, average pupal weight was highest on J. parasitica (450.66 mg vs. 420.01 mg), although this difference was least apparent in M. mothone. We did not find that coexisting species of Melinaea partition host plant resources as expected if speciation is primarily driven by host plant divergence. Although M. mothone shows evidence of local adaptation to a novel host plant, T. speciosa, which co-occurs, it does not preferentially lay more eggs on or perform better on this host plant than on host plants used by other Melinaea species and not present in its distributional range. It is likely that diversification in this genus is driven by co-occurring Müllerian mimics and the resulting predation pressure, although this is also likely made possible by greater niche diversity as a consequence of plasticity for potential hosts.

Rapidly Evolving Transients in the Dark Energy Survey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pursiainen, M.; et al.

We present the results of a search for rapidly evolving transients in the Dark Energy Survey Supernova Programme. These events are characterized by fast light curve evolution (rise to peak inmore » $$\\lesssim 10$$ d and exponential decline in $$\\lesssim30$$ d after peak). We discovered 72 events, including 37 transients with a spectroscopic redshift from host galaxy spectral features. The 37 events increase the total number of rapid optical transients by more than factor of two. They are found at a wide range of redshifts ($0.05M_\\mathrm{g}>-22.25$$). The multiband photometry is well fit by a blackbody up to few weeks after peak. The events appear to be hot ($$T\\approx10000-30000$$ K) and large ($$R\\approx 10^{14}-2\\cdot10^{15}$$ cm) at peak, and generally expand and cool in time, though some events show evidence for a receding photosphere with roughly constant temperature. Spectra taken around peak are dominated by a blue featureless continuum consistent with hot, optically thick ejecta. We compare our events with a previously suggested physical scenario involving shock breakout in an optically thick wind surrounding a core-collapse supernova (CCSNe), we conclude that current models for such a scenario might need an additional power source to describe the exponential decline. We find these transients tend to favor star-forming host galaxies, which could be consistent with a core-collapse origin. However, more detailed modeling of the light curves is necessary to determine their physical origin.« less

NK Cells and Other Innate Lymphoid Cells in Hematopoietic Stem Cell Transplantation.

PubMed

Vacca, Paola; Montaldo, Elisa; Croxatto, Daniele; Moretta, Francesca; Bertaina, Alice; Vitale, Chiara; Locatelli, Franco; Mingari, Maria Cristina; Moretta, Lorenzo

2016-01-01

Natural killer (NK) cells play a major role in the T-cell depleted haploidentical hematopoietic stem cell transplantation (haplo-HSCT) to cure high-risk leukemias. NK cells belong to the expanding family of innate lymphoid cells (ILCs). At variance with NK cells, the other ILC populations (ILC1/2/3) are non-cytolytic, while they secrete different patterns of cytokines. ILCs provide host defenses against viruses, bacteria, and parasites, drive lymphoid organogenesis, and contribute to tissue remodeling. In haplo-HSCT patients, the extensive T-cell depletion is required to prevent graft-versus-host disease (GvHD) but increases risks of developing a wide range of life-threatening infections. However, these patients may rely on innate defenses that are reconstituted more rapidly than the adaptive ones. In this context, ILCs may represent important players in the early phases following transplantation. They may contribute to tissue homeostasis/remodeling and lymphoid tissue reconstitution. While the reconstitution of NK cell repertoire and its role in haplo-HSCT have been largely investigated, little information is available on ILCs. Of note, CD34(+) cells isolated from different sources of HSC may differentiate in vitro toward various ILC subsets. Moreover, cytokines released from leukemia blasts (e.g., IL-1β) may alter the proportions of NK cells and ILC3, suggesting the possibility that leukemia may skew the ILC repertoire. Further studies are required to define the timing of ILC development and their potential protective role after HSCT.

The silent mass extinction of insect herbivores in biodiversity hotspots.

PubMed

Fonseca, Carlos Roberto

2009-12-01

Habitat loss is silently leading numerous insects to extinction. Conservation efforts, however, have not been designed specifically to protect these organisms, despite their ecological and evolutionary significance. On the basis of species-host area equations, parameterized with data from the literature and interviews with botanical experts, I estimated the number of specialized plant-feeding insects (i.e., monophages) that live in 34 biodiversity hotspots and the number committed to extinction because of habitat loss. I estimated that 795,971-1,602,423 monophagous insect species live in biodiversity hotspots on 150,371 endemic plant species, which is 5.3-10.6 monophages per plant species. I calculated that 213,830-547,500 monophagous species are committed to extinction in biodiversity hotspots because of reduction of the geographic range size of their endemic hosts. I provided rankings of biodiversity hotspots on the basis of estimated richness of monophagous insects and on estimated number of extinctions of monophagous species. Extinction rates were predicted to be higher in biodiversity hotspots located along strong environmental gradients and on archipelagos, where high spatial turnover of monophagous species along the geographic distribution of their endemic plants is likely. The results strongly support the overall strategy of selecting priority conservation areas worldwide primarily on the basis of richness of endemic plants. To face the global decline of insect herbivores, one must expand the coverage of the network of protected areas and improve the richness of native plants on private lands.

Evolving models of the immunopathogenesis of T-cell mediated drug allergy: the role of host, pathogens, and drug response

PubMed Central

White, Katie D.; Chung, Wen-Hung; Hung, Shuen-Iu; Mallal, Simon; Phillips, Elizabeth J.

2015-01-01

Immune-mediated adverse drug reactions (IM-ADRs) are an underrecognized source of preventable morbidity, mortality, and cost. Increasingly, genetic variation in the HLA loci is associated with risk of severe reactions, highlighting the importance of T-cell immune responses in the mechanisms of both B-cell mediated and primary T-cell mediated IM-ADRs. In this review, we summarize the role of host genetics, microbes and drugs in the development of IM-ADRs, expand upon the existing models of IM-ADR pathogenesis to address multiple unexplained observations, discuss the implications of this work in clinical practice today, and describe future applications for pre-clinical drug toxicity screening, drug design, and development. PMID:26254049

Influence of leaf color in a dry bean mapping population on Empoasca sp. populations and host plant resistance.

USDA-ARS?s Scientific Manuscript database

Visual cues may be the first line of host plant recognition and an important determining factor when selecting host plants for feeding and oviposition, especially for highly polyphagous insects, such as leafhoppers, which have a broad range of potential host plants. Temperate Empoasca fabae and trop...

The Metallophore Staphylopine Enables Staphylococcus aureus To Compete with the Host for Zinc and Overcome Nutritional Immunity.

PubMed

Grim, Kyle P; San Francisco, Brian; Radin, Jana N; Brazel, Erin B; Kelliher, Jessica L; Párraga Solórzano, Paola K; Kim, Philip C; McDevitt, Christopher A; Kehl-Fie, Thomas E

2017-10-31

During infection, the host sequesters essential nutrients, such as zinc, to combat invading microbes. Despite the ability of the immune effector protein calprotectin to bind zinc with subpicomolar affinity, Staphylococcus aureus is able to successfully compete with the host for zinc. However, the zinc importers expressed by S. aureus remain unknown. Our investigations have revealed that S. aureus possesses two importers, AdcABC and CntABCDF, which are induced in response to zinc limitation. While AdcABC is similar to known zinc importers in other bacteria, CntABCDF has not previously been associated with zinc acquisition. Concurrent loss of the two systems severely impairs the ability of S. aureus to obtain zinc and grow in zinc-limited environments. Further investigations revealed that the Cnt system is responsible for the ability of S. aureus to compete with calprotectin for zinc in culture and contributes to acquisition of zinc during infection. The cnt locus also enables S. aureus to produce the broad-spectrum metallophore staphylopine. Similarly to the Cnt transporter, loss of staphylopine severely impairs the ability of S. aureus to resist host-imposed zinc starvation, both in culture and during infection. Further investigations revealed that together staphylopine and the Cnt importer function analogously to siderophore-based iron acquisition systems in order to facilitate zinc acquisition by S. aureus Analogous systems are found in a broad range of Gram-positive and Gram-negative bacterial pathogens, suggesting that this new type of zinc importer broadly contributes to the ability of bacteria to cause infection. IMPORTANCE A critical host defense against infection is the restriction of zinc availability. Despite the subpicomolar affinity of the immune effector calprotectin for zinc, Staphylococcus aureus can successfully compete for this essential metal. Here, we describe two zinc importers, AdcABC and CntABCDF, possessed by S. aureus , the latter of which has not previously been associated with zinc acquisition. The ability of S. aureus to compete with the host for zinc is dependent on CntABCDF and the metallophore staphylopine, both in culture and during infection. These results expand the mechanisms utilized by bacteria to obtain zinc, beyond Adc-like systems, and demonstrate that pathogens utilize strategies similar to siderophore-based iron acquisition to obtain other essential metals during infection. The staphylopine synthesis machinery is present in a diverse collection of bacteria, suggesting that this new family of zinc importers broadly contributes to the ability of numerous pathogens to cause infection. Copyright © 2017 Grim et al.

Molecular epidemiology and evolution of fish Novirhabdoviruses

USGS Publications Warehouse

Kurath, Gael

2014-01-01

The genus Novirhabdoviridae contains several of the important rhabdoviruses that infect fish hosts. There are four established virus species: Infectious hematopoietic necrosis virus (IHNV), Viral hemorrhagic septicemia virus (VHSV), Hirame rhabdovirus(HIRRV), and Snakehead rhabdovirus (SHRV). Viruses of these species vary in host and geographic range, and they have all been studied at the molecular and genomic level. As globally significant pathogens of cultured fish, IHNV and VHSV have been particularly well studied in terms of molecular epidemiology and evolution. Phylogenic analyses of hundreds of field isolates have defined five major genogroups of IHNV and four major genotypes of VHSV worldwide. These phylogenies are informed by the known histories of IHNV and VHSV, each involving a series of viral emergence events that are sometimes associated with host switches, most often into cultured rainbow trout. In general, IHNV has relatively low genetic diversity and a narrow host range, and has been spread from its endemic source in North American to Europe and Asia due to aquaculture activities. In contrast, VHSV has broad host range and high genetic diversity, and the source of emergence events is virus in widespread marine fish reservoirs in the northern Atlantic and Pacific Oceans. Common mechanisms of emergence and host switch events include use of raw feed, proximity to wild fish reservoirs of virus, and geographic translocations of virus or naive fish hosts associated with aquaculture.

Aphids (Hemiptera, Aphididae) on ornamental plants in greenhouses in Bulgaria

PubMed Central

Yovkova, Mariya; Petrović-Obradović, Olivera; Tasheva-Terzieva, Elena; Pencheva, Aneliya

2013-01-01

Abstract Investigations on the species composition and host range of aphids on ornamental greenhouse plants in Bulgaria was conducted over a period of five years, from 2008 to 2012. Twenty greenhouses, growing ornamentals for landscaping, plant collections and other purposes were observed. They were located in the regions of Sofia, Plovdiv, Smolyan, Pavlikeni, Varna and Burgas. The total number of collected aphid samples was 279. Their composition included 33 aphid species and one subspecies from 13 genera and 5 subfamilies. Twenty-eight species were found to belong to subfamily Aphidinae. Almost 70 % of all recorded species were polyphagous. The most widespread aphid species was Myzus persicae, detected in 13 greenhouses all year round, followed by Aulacorthum solani (10 greenhouses) and Aphis gossypii (9 greenhouses). The widest host range was shown by Myzus persicae (43 hosts), Aulacorthum solani (32 hosts) and Aulacorthum circumflexum (23 hosts). The list of host plants includes 114 species from 95 genera and 58 families. The greatest variety of aphid species was detected on Hibiscus (9 species). Out of all aphid samples 12.9 % were collected on Hibiscus and 6.8 %, on Dendranthema. The greatest variety of aphid species was detected on Hibiscus (9 species). Periphyllus californiensis and Aphis (Aphis) fabae mordvilkoi are reported for the first time for Bulgaria. Furthermore, Aphis spiraecola has been found in new localities and has widened its host range in this country. PMID:24039530

Detection and Characterization of Homologues of Human Hepatitis Viruses and Pegiviruses in Rodents and Bats in Vietnam

PubMed Central

Van Nguyen, Cuong; Bonsall, David; Ngo, Tue Tri; Carrique-Mas, Juan; Pham, Anh Hong; Bryant, Juliet E.; Thwaites, Guy; Baker, Stephen; Woolhouse, Mark; Simmonds, Peter

2018-01-01

Rodents and bats are now widely recognised as important sources of zoonotic virus infections in other mammals, including humans. Numerous surveys have expanded our knowledge of diverse viruses in a range of rodent and bat species, including their origins, evolution, and range of hosts. In this study of pegivirus and human hepatitis-related viruses, liver and serum samples from Vietnamese rodents and bats were examined by PCR and sequencing. Nucleic acids homologous to human hepatitis B, C, E viruses were detected in liver samples of 2 (1.3%) of 157 bats, 38 (8.1%), and 14 (3%) of 470 rodents, respectively. Hepacivirus-like viruses were frequently detected (42.7%) in the bamboo rat, Rhizomys pruinosus, while pegivirus RNA was only evident in 2 (0.3%) of 638 rodent serum samples. Complete or near-complete genome sequences of HBV, HEV and pegivirus homologues closely resembled those previously reported from rodents and bats. However, complete coding region sequences of the rodent hepacivirus-like viruses substantially diverged from all of the currently classified variants and potentially represent a new species in the Hepacivirus genus. Of the viruses identified, their routes of transmission and potential to establish zoonoses remain to be determined. PMID:29495551

Mycoplasmosis and upper respiratory tract disease of tortoises: a review and update

USGS Publications Warehouse

Jacobson, Elliott R.; Brown, Mary B.; Wendland, Lori; Brown, Daniel R.; Klein, Paul A.; Christopher, Mary M.; Berry, Kristin H.

2014-01-01

Tortoise mycoplasmosis is one of the most extensively characterized infectious diseases of chelonians. A 1989 outbreak of upper respiratory tract disease (URTD) in free-ranging Agassiz's desert tortoises (Gopherus agassizii) brought together an investigative team of researchers, diagnosticians, pathologists, immunologists and clinicians from multiple institutions and agencies. Electron microscopic studies of affected tortoises revealed a microorganism in close association with the nasal mucosa that subsequently was identified as a new species, Mycoplasma agassizii. Over the next 24 years, a second causative agent, Mycoplasma testudineum, was discovered, the geographic distribution and host range of tortoise mycoplasmosis were expanded, diagnostic tests were developed and refined for antibody and pathogen detection, transmission studies confirmed the pathogenicity of the original M. agassizii isolate, clinical (and subclinical) disease and laboratory abnormalities were characterized, many extrinsic and predisposing factors were found to play a role in morbidity and mortality associated with mycoplasmal infection, and social behavior was implicated in disease transmission. The translation of scientific research into management decisions has sometimes led to undesirable outcomes, such as euthanasia of clinically healthy tortoises. In this article, we review and assess current research on tortoise mycoplasmosis, arguably the most important chronic infectious disease of wild and captive North American and European tortoises, and update the implications for management and conservation of tortoises in the wild.

Comparative whole genome analysis of six diagnostic brucellaphages.

PubMed

Farlow, Jason; Filippov, Andrey A; Sergueev, Kirill V; Hang, Jun; Kotorashvili, Adam; Nikolich, Mikeljon P

2014-05-15

Whole genome sequencing of six diagnostic brucellaphages, Tbilisi (Tb), Firenze (Fz), Weybridge (Wb), S708, Berkeley (Bk) and R/C, was followed with genomic comparisons including recently described genomes of the Tb phage from Mexico (TbM) and Pr phage to elucidate genomic diversity and candidate host range determinants. Comparative whole genome analysis revealed high sequence homogeneity among these brucellaphage genomes and resolved three genetic groups consistent with defined host range phenotypes. Group I was composed of Tb and Fz phages that are predominantly lytic for Brucella abortus and Brucella neotomae; Group II included Bk, R/C, and Pr phages that are lytic mainly for B. abortus, Brucella melitensis and Brucella suis; Group III was composed of Wb and S708 phages that are lytic for B. suis, B. abortus and B. neotomae. We found that the putative phage collar protein is a variable locus with features that may be contributing to the host specificities exhibited by different brucellaphage groups. The presence of several candidate host range determinants is illustrated herein for future dissection of the differential host specificity observed among these phages. Published by Elsevier B.V.

Water-deficit and fungal infection can differentially affect the production of different classes of defense compounds in two host pines of mountain pine beetle.

PubMed

Erbilgin, Nadir; Cale, Jonathan A; Lusebrink, Inka; Najar, Ahmed; Klutsch, Jennifer G; Sherwood, Patrick; Enrico Bonello, Pierluigi; Evenden, Maya L

2017-03-01

Bark beetles are important agents of tree mortality in conifer forests and their interaction with trees is influenced by host defense chemicals, such as monoterpenes and phenolics. Since mountain pine beetle (Dendroctonus ponderosae Hopkins) has expanded its host range from lodgepole pine (Pinus contorta Doug. ex Loud. (var. latifolia Engelm.))-dominated forests to the novel jack pine (Pinus banksiana Lamb.) forests in western Canada, studies investigating the jack pine suitability as a host for this beetle have exclusively focused on monoterpenes, and whether phenolics affect jack pine suitability to mountain pine beetle and its symbiotic fungus Grosmannia clavigera is unknown. We investigated the phenolic and monoterpene composition in phloem and foliage of jack and lodgepole pines, and their subsequent change in response to water deficit and G. clavigera inoculation treatments. In lodgepole pine phloem, water deficit treatment inhibited the accumulation of both the total and richness of phenolics, but had no effect on total monoterpene production or richness. Fungal infection also inhibited the total phenolic production and had no effect on phenolic or monoterpene richness, but increased total monoterpene synthesis by 71%. In jack pine phloem, water deficit treatment reduced phenolic production, but had no effect on phenolic or monoterpene richness or total monoterpenes. Fungal infection did not affect phenolic or monoterpene production. Lesions of both species contained lower phenolics but higher monoterpenes than non-infected phloem in the same tree. In both species, richness of monoterpenes and phenolics was greater in non-infected phloem than in lesions. We conclude that monoterpenes seem to be a critical component of induced defenses against G. clavigera in both jack and lodgepole pines; however, a lack of increased monoterpene response to fungal infection is an important evolutionary factor defining jack pine suitability to the mountain pine beetle invasion in western Canada. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Are adaptation costs necessary to build up a local adaptation pattern?

PubMed

Magalhães, Sara; Blanchet, Elodie; Egas, Martijn; Olivieri, Isabelle

2009-08-03

Ecological specialization is pervasive in phytophagous arthropods. In such specialization mode, limits to host range are imposed by trade-offs preventing adaptation to several hosts. The occurrence of such trade-offs is inferred by a pattern of local adaptation, i.e., a negative correlation between relative performance on different hosts. To establish a causal link between local adaptation and trade-offs, we performed experimental evolution of spider mites on cucumber, tomato and pepper, starting from a population adapted to cucumber. Spider mites adapted to each novel host within 15 generations and no further evolution was observed at generation 25. A pattern of local adaptation was found, as lines evolving on a novel host performed better on that host than lines evolving on other hosts. However, costs of adaptation were absent. Indeed, lines adapted to tomato had similar or higher performance on pepper than lines evolving on the ancestral host (which represent the initial performance of all lines) and the converse was also true, e.g. negatively correlated responses were not observed on the alternative novel host. Moreover, adapting to novel hosts did not result in decreased performance on the ancestral host. Adaptation did not modify host ranking, as all lines performed best on the ancestral host. Furthermore, mites from all lines preferred the ancestral to novel hosts. Mate choice experiments indicated that crosses between individuals from the same or from a different selection regime were equally likely, hence development of reproductive isolation among lines adapted to different hosts is unlikely. Therefore, performance and preference are not expected to impose limits to host range in our study species. Our results show that the evolution of a local adaptation pattern is not necessarily associated with the evolution of an adaptation cost.

Shack-Hartmann wavefront sensor with large dynamic range by adaptive spot search method.

PubMed

Shinto, Hironobu; Saita, Yusuke; Nomura, Takanori

2016-07-10

A Shack-Hartmann wavefront sensor (SHWFS) that consists of a microlens array and an image sensor has been used to measure the wavefront aberrations of human eyes. However, a conventional SHWFS has finite dynamic range depending on the diameter of the each microlens. The dynamic range cannot be easily expanded without a decrease of the spatial resolution. In this study, an adaptive spot search method to expand the dynamic range of an SHWFS is proposed. In the proposed method, spots are searched with the help of their approximate displacements measured with low spatial resolution and large dynamic range. By the proposed method, a wavefront can be correctly measured even if the spot is beyond the detection area. The adaptive spot search method is realized by using the special microlens array that generates both spots and discriminable patterns. The proposed method enables expanding the dynamic range of an SHWFS with a single shot and short processing time. The performance of the proposed method is compared with that of a conventional SHWFS by optical experiments. Furthermore, the dynamic range of the proposed method is quantitatively evaluated by numerical simulations.

Eight new Arthrinium species from China

PubMed Central

Wang, Mei; Tan, Xiao-Ming; Liu, Fang; Cai, Lei

2018-01-01

Abstract The genus Arthrinium includes important plant pathogens, endophytes and saprobes with a wide host range and geographic distribution. In this paper, 74 Arthrinium strains isolated from various substrates such as bamboo leaves, tea plants, soil and air from karst caves in China were examined using a multi-locus phylogeny based on a combined dataset of ITS rDNA, TEF1 and TUB2, in conjunction with morphological characters, host association and ecological distribution. Eight new species were described based on their distinct phylogenetic relationships and morphological characters. Our results indicated a high species diversity of Arthrinium with wide host ranges, amongst which, Poaceae and Cyperaceae were the major host plant families of Arthrinium species. PMID:29755262

Eight new Arthrinium species from China.

PubMed

Wang, Mei; Tan, Xiao-Ming; Liu, Fang; Cai, Lei

2018-01-01

The genus Arthrinium includes important plant pathogens, endophytes and saprobes with a wide host range and geographic distribution. In this paper, 74 Arthrinium strains isolated from various substrates such as bamboo leaves, tea plants, soil and air from karst caves in China were examined using a multi-locus phylogeny based on a combined dataset of ITS rDNA, TEF1 and TUB2, in conjunction with morphological characters, host association and ecological distribution. Eight new species were described based on their distinct phylogenetic relationships and morphological characters. Our results indicated a high species diversity of Arthrinium with wide host ranges, amongst which, Poaceae and Cyperaceae were the major host plant families of Arthrinium species.

Phylogenetic relationships and host range of Rhizobium spp. that nodulate Phaseolus vulgaris L.

PubMed

Hernandez-Lucas, I; Segovia, L; Martinez-Romero, E; Pueppke, S G

1995-07-01

We determined the nucleotide sequences of 16S rRNA gene segments from five Rhizobium strains that have been isolated from tropical legume species. All share the capacity to nodulate Phaseolus vulgaris L., the common bean. Phylogenetic analysis confirmed that these strains are of two different chromosomal lineages. We defined the host ranges of two strains of Rhizobium etli and three strains of R. tropici, comparing them with those of the two most divergently related new strains. Twenty-two of the 43 tested legume species were nodulated by three or more of these strains. All seven strains have broad host ranges that include woody species such as Albizia lebbeck, Gliricidia maculata, and Leucaena leucocephala.

Myxoma Virus M064 Is a Novel Member of the Poxvirus C7L Superfamily of Host Range Factors That Controls the Kinetics of Myxomatosis in European Rabbits

PubMed Central

Liu, Jia; Wennier, Sonia; Moussatche, Nissin; Reinhard, Mary; Condit, Richard

2012-01-01

The myxoma virus (MYXV) carries three tandem C7L-like host range genes (M062R, M063R, and M064R). However, despite the fact that the sequences of these three genes are similar, they possess very distinctive functions in vivo. The role of M064 in MYXV pathogenesis was investigated and compared to the roles of M062 and M063. We report that M064 is a virulence factor that contributes to MYXV pathogenesis but lacks the host range properties associated with M062 and M063. PMID:22379095

Myxoma virus M064 is a novel member of the poxvirus C7L superfamily of host range factors that controls the kinetics of myxomatosis in European rabbits.

PubMed

Liu, Jia; Wennier, Sonia; Moussatche, Nissin; Reinhard, Mary; Condit, Richard; McFadden, Grant

2012-05-01

The myxoma virus (MYXV) carries three tandem C7L-like host range genes (M062R, M063R, and M064R). However, despite the fact that the sequences of these three genes are similar, they possess very distinctive functions in vivo. The role of M064 in MYXV pathogenesis was investigated and compared to the roles of M062 and M063. We report that M064 is a virulence factor that contributes to MYXV pathogenesis but lacks the host range properties associated with M062 and M063.

Europlanet Integrated and Distributed Information Service

NASA Astrophysics Data System (ADS)

Schmidt, W.; Capria, M. T.; Chanteur, G.

2009-04-01

During the past decades the various disciplines in planetary sciences have developed to a very high international standard. But the collaboration between the different fields should be improved. To overcome the current fragmentation of the EU Planetary Science community and thereby to increase the scientific return of the related investment, the EU commission is funding via its Framework Program 7 the development of the "Europlanet Research Infrastructure -Europlanet RI". The Europlanet RI will consolidate the integration of the European Planetary Science community which started with Europlanet's FP6 project and will integrate major parts of the related distributed European infrastructure to be shared, fed and expanded by all planetary scientists. This infrastructure encompasses as diverse components as space exploration, ground-based observations, laboratory experiments and numerical modeling teams. Europlanet RI aims at bringing scientists from Europe and beyond together who are working in these fields, support the exchange of experts and ideas and make as many resources and data as possible available to the research community. A central part of Europlanet RI is the "Integrated and Distributed Information Service" or Europlanet-IDIS. The task of IDIS as central part of Europlanet is to provide an easy-to-use Web-based platform to locate teams and laboratories with special knowledge needed to support the own research activities, give access to the wealth of already available data, initiate new research activities needed to interpret accumulated data or to solve open questions, and to exploit synergies between space-based missions and capabilities of ground based observatories. It also offers to a wide range of teams and laboratories the possibility to share their data, advertise their capabilities and increase the scientific return by cooperation. IDIS is organized as an EU FP7 Support Activity, consisting of different access nodes which are connected by integrated search facilities, compatible structures and a common management. Each of these nodes concentrates on a special field of planetary sciences, has its own team of related international experts and is responsible for the access to information and data centres related to its area of competence. Integrated keyword-based search-possibilities direct inquiries to those node(s), most likely to return the wanted information. These nodes are hosted by the following organizations: - The Finnish Meteorological Institute (FMI) in Helsinki, Finland, hosts the Technical Node for a wide range of support activities and provides the network management. - The Institute of Planetary Research (IPR) of DLR in Berlin, Germany, hosts the Planetary Surfaces and Interiors Node, concentrating on internal structure, formation and evolution of the planets, their moons, asteroids and comets. - The Institut für Weltraumforschung, IWF (Space Research Institute) of the Austrian Academy of Sciences (OeAW) in Graz hosts the Planetary Plasma Node in close cooperation with the French space plasma data center CDPP in Toulouse. - The Institut Pierre-Simon Laplace in Paris hosts the Planetary Atmospheres Node. - The Paris Observatory hosts the Virtual Observatory Paris Data Center providing among others access to a wide range of atomic and molecular spectral databases. - The Istituto di Fisica dello Spazio Interplanetario (IFSI) in Rome hosts the Small Bodies and Dust Node, in cooperation with the ESA/ESTECs Virtual Meteor Observatory in Noordwijk, The Netherlands, concentrating on research and observations related to solar system asteroids, comets, meteors and interplanetary dust. During the next four years a set of tools for describing, accessing and combining information and data from different sources will be developed, offering finally a Virtual Observatory like access to many data essential for planetary research from European and None-European sources. Web access via any of the mentioned nodes, e.g. the Technical Node at http://www.europlanet-idis.fi/

Interannual variability of human plague occurrence in the Western United States explained by tropical and North Pacific Ocean climate variability.

PubMed

Ari, Tamara Ben; Gershunov, Alexander; Tristan, Rouyer; Cazelles, Bernard; Gage, Kenneth; Stenseth, Nils C

2010-09-01

Plague is a vector-borne, highly virulent zoonotic disease caused by the bacterium Yersinia pestis. It persists in nature through transmission between its hosts (wild rodents) and vectors (fleas). During epizootics, the disease expands and spills over to other host species such as humans living in or close to affected areas. Here, we investigate the effect of large-scale climate variability on the dynamics of human plague in the western United States using a 56-year time series of plague reports (1950-2005). We found that El Niño Southern Oscillation and Pacific Decadal Oscillation in combination affect the dynamics of human plague over the western United States. The underlying mechanism could involve changes in precipitation and temperatures that impact both hosts and vectors. It is suggested that snow also may play a key role, possibly through its effects on summer soil moisture, which is known to be instrumental for flea survival and development and sustained growth of vegetation for rodents.

Interspecific Germline Transmission of Cultured Primordial Germ Cells

PubMed Central

van de Lavoir, Marie-Cecile; Collarini, Ellen J.; Leighton, Philip A.; Fesler, Jeffrey; Lu, Daniel R.; Harriman, William D.; Thiyagasundaram, T. S.; Etches, Robert J.

2012-01-01

In birds, the primordial germ cell (PGC) lineage separates from the soma within 24 h following fertilization. Here we show that the endogenous population of about 200 PGCs from a single chicken embryo can be expanded one million fold in culture. When cultured PGCs are injected into a xenogeneic embryo at an equivalent stage of development, they colonize the testis. At sexual maturity, these donor PGCs undergo spermatogenesis in the xenogeneic host and become functional sperm. Insemination of semen from the xenogeneic host into females from the donor species produces normal offspring from the donor species. In our model system, the donor species is chicken (Gallus domesticus) and the recipient species is guinea fowl (Numida meleagris), a member of a different avian family, suggesting that the mechanisms controlling proliferation of the germline are highly conserved within birds. From a pragmatic perspective, these data are the basis of a novel strategy to produce endangered species of birds using domesticated hosts that are both tractable and fecund. PMID:22629301

Dynamics of Fermionic Impurity in One Dimension

NASA Astrophysics Data System (ADS)

Guan, Huijie; Andrei, Natan

2014-03-01

We study the dynamics of a fermionic impurity propagating in a one dimensional infinite line. The system is described by the Gaudin-Yang Model and is exactly solvable by the Nested Bethe Ansatz. Starting from a generic initial state, we obtain the time evolution of the wavefunction by the Yudson Approach in which we expand the initial state with the Nested Bethe Ansatz solutions. One situation that we are interested in is where, initially, the impurity is embedded in host fermions with a lattice configuration and one remove the periodic potential at time zero. We calculate the density profile and correlation functions at a later time. Another situation is to shoot an impurity into a cloud of fermions and calculate the probability for it to pass through. While the repulsive case has been studied already[1], we extend it to the attractive case and study the role of bound states in the evolution. We are also interested in boson impurity problem, where not only impurity interacts with host particles, all host particles interact with each other.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roux, Simon; Hawley, Alyse K.; Torres Beltran, Monica

Viruses modulate microbial communities and alter ecosystem functions. However, due to cultivation bottlenecks, specific virus–host interaction dynamics remain cryptic. In this study, we examined 127 single-cell amplified genomes (SAGs) from uncultivated SUP05 bacteria isolated from a model marine oxygen minimum zone (OMZ) to identify 69 viral contigs representing five new genera within dsDNA Caudovirales and ssDNA Microviridae. Infection frequencies suggest that ∼1/3 of SUP05 bacteria is viral-infected, with higher infection frequency where oxygen-deficiency was most severe. Observed Microviridae clonality suggests recovery of bloom-terminating viruses, while systematic co-infection between dsDNA and ssDNA viruses posits previously unrecognized cooperation modes. Analyses of 186more » microbial and viral metagenomes revealed that SUP05 viruses persisted for years, but remained endemic to the OMZ. Finally, identification of virus-encoded dissimilatory sulfite reductase suggests SUP05 viruses reprogram their host's energy metabolism. Together, these results demonstrate closely coupled SUP05 virus–host co-evolutionary dynamics with the potential to modulate biogeochemical cycling in climate-critical and expanding OMZs.« less

Genome and metagenome analyses reveal adaptive evolution of the host and interaction with the gut microbiota in the goose

PubMed Central

Gao, Guangliang; Zhao, Xianzhi; Li, Qin; He, Chuan; Zhao, Wenjing; Liu, Shuyun; Ding, Jinmei; Ye, Weixing; Wang, Jun; Chen, Ye; Wang, Haiwei; Li, Jing; Luo, Yi; Su, Jian; Huang, Yong; Liu, Zuohua; Dai, Ronghua; Shi, Yixiang; Meng, He; Wang, Qigui

2016-01-01

The goose is an economically important waterfowl that exhibits unique characteristics and abilities, such as liver fat deposition and fibre digestion. Here, we report de novo whole-genome assemblies for the goose and swan goose and describe the evolutionary relationships among 7 bird species, including domestic and wild geese, which diverged approximately 3.4~6.3 million years ago (Mya). In contrast to chickens as a proximal species, the expanded and rapidly evolving genes found in the goose genome are mainly involved in metabolism, including energy, amino acid and carbohydrate metabolism. Further integrated analysis of the host genome and gut metagenome indicated that the most widely shared functional enrichment of genes occurs for functions such as glycolysis/gluconeogenesis, starch and sucrose metabolism, propanoate metabolism and the citrate cycle. We speculate that the unique physiological abilities of geese benefit from the adaptive evolution of the host genome and symbiotic interactions with gut microbes. PMID:27608918

JPRS Report, Science & Technology, China, High-Performance Computer Systems

DTIC Science & Technology

1992-10-28

microprocessor array The microprocessor array in the AP85 system is com- posed of 16 completely identical array element micro - processors . Each array element...microprocessors and capable of host machine reading and writing. The memory capacity of the array element micro - processors as a whole can be expanded...transmission functions to carry out data transmission from array element micro - processor to array element microprocessor, from array element

Wind for Schools: Developing Education Programs to Train the Next Generation of the Wind Energy Workforce

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.; Flowers, L.; Kelly, M.

2009-08-01

This paper provides an overview of the Wind for Schools project elements, including a description of host and collegiate school curricula developed for wind energy and the status of the current projects. The paper also provides focused information on how schools, regions, or countries can become involved or implement similar projects to expand the social acceptance and understanding of wind energy.

Expanding the chemical palate of cells by combining systems biology and metabolic engineering.

PubMed

Curran, Kathleen A; Alper, Hal S

2012-07-01

The field of Metabolic Engineering has recently undergone a transformation that has led to a rapid expansion of the chemical palate of cells. Now, it is conceivable to produce nearly any organic molecule of interest using a cellular host. Significant advances have been made in the production of biofuels, biopolymers and precursors, pharmaceuticals and nutraceuticals, and commodity and specialty chemicals. Much of this rapid expansion in the field has been, in part, due to synergies and advances in the area of systems biology. Specifically, the availability of functional genomics, metabolomics and transcriptomics data has resulted in the potential to produce a wealth of new products, both natural and non-natural, in cellular factories. The sheer amount and diversity of this data however, means that uncovering and unlocking novel chemistries and insights is a non-obvious exercise. To address this issue, a number of computational tools and experimental approaches have been developed to help expedite the design process to create new cellular factories. This review will highlight many of the systems biology enabling technologies that have reduced the design cycle for engineered hosts, highlight major advances in the expanded diversity of products that can be synthesized, and conclude with future prospects in the field of metabolic engineering. Copyright © 2012 Elsevier Inc. All rights reserved.

Contrasting determinants of abundance in ancestral and colonized ranges of an invasive brood parasite

USGS Publications Warehouse

Hahn, D.C.; O'Connor, R.J.; Scott, J. Michael; Heglund, Patricia J.; Morrison, Michael L.; Haufler, Jonathan B.; Wall, William A.

2002-01-01

Avian species distributions are typically regarded as constrained by spatially extensive variables such as climate, habitat, spatial patchiness, and microhabitat attributes. We hypothesized that the distribution of a brood parasite depends as strongly on host distribution patterns as on biophysical factors and examined this hypothesis with respect to the national distribution of the Brown-headed Cowbird (Molothrus ater). We applied a classification and regression (CART) analysis to data from the Breeding Bird Survey (BBS) and the Christmas Bird Count (CBC) and derived hierarchically organized statistical models of the influence of climate and weather, cropping and land use, and host abundance and distribution on the distribution of the Brown-headed Cowbird within the conterminous United States. The model accounted for 47.2% of the variation in cowbird incidence, and host abundance was the top predictor with an R2 of 18.9%. The other predictors identified by the model (crops 15.7%, weather and climate 14.3%, and region 9.6%) fit the ecological profile of this cowbird. We showed that host abundance was independent of these environmental predictors of cowbird distribution. At the regional scale host abundance played a very strong role in determining cowbird abundance in the cowbird?s colonized range east and west of their ancestral range in the Great Plains (26.6%). Crops were not a major predictor for cowbirds in their ancestral range, although they are the most important predictive factor (33%) for the grassland passerines that are the cowbird?s ancestral hosts. Consequently our findings suggest that the distribution of hosts does indeed take precedence over habitat attributes in shaping the cowbird?s distribution at a national scale, within an envelope of constraint set by biophysical factors.

Prevalence and differential host-specificity of two avian blood parasite genera in the Australo-Papuan region

USGS Publications Warehouse

Beadell, J.S.; Gering, E.; Austin, J.; Dumbacher, J.P.; Peirce, M.A.; Pratt, T.K.; Atkinson, C.T.; Fleischer, R.C.

2004-01-01

The degree to which widespread avian blood parasites in the genera Plasmodium and Haemoproteus pose a threat to novel hosts depends in part on the degree to which they are constrained to a particular host or host family. We examined the host distribution and host-specificity of these parasites in birds from two relatively understudied and isolated locations: Australia and Papua New Guinea. Using polymerase chain reaction (PCR), we detected infection in 69 of 105 species, representing 44% of individuals surveyed (n = 428). Across host families, prevalence of Haemoproteus ranged from 13% (Acanthizidae) to 56% (Petroicidae) while prevalence of Plasmodium ranged from 3% (Petroicidae) to 47% (Ptilonorhynchidae). We recovered 78 unique mitochondrial lineages from 155 sequences. Related lineages of Haemoproteus were more likely to derive from the same host family than predicted by chance at shallow (average LogDet genetic distance = 0, n = 12, P = 0.001) and greater depths (average distance = 0.014, n = 11, P < 0.001) within the parasite phylogeny. Within two major Haemoproteus subclades identified in a maximum likelihood phylogeny, host-specificity was evident up to parasite genetic distances of 0.029 and 0.007 based on logistic regression. We found no significant host relationship among lineages of Plasmodium by any method of analysis. These results support previous evidence of strong host-family specificity in Haemoproteus and suggest that lineages of Plasmodium are more likely to form evolutionarily-stable associations with novel hosts.

Online purchases of an expanded range of condom sizes in comparison to current dimensional requirements allowable by US national standards.

PubMed

Cecil, Michael; Warner, Lee; Siegler, Aaron J

2013-11-01

Across studies, 35-50% of men describe condoms as fitting poorly. Rates of condom use may be inhibited in part due to the inaccessibility of appropriately sized condoms. As regulated medical devices, condom sizes conform to national standards such as those developed by the American Society for Testing and Materials (ASTM) or international standards such as those developed by the International Organisation for Standardisation (ISO). We describe the initial online sales experience of an expanded range of condom sizes and assess uptake in relation to the current required standard dimensions of condoms. Data regarding the initial 1000 sales of an expanded range of condom sizes in the United Kingdom were collected from late 2011 through to early 2012. Ninety-five condom sizes, comprising 14 lengths (83-238mm) and 12 widths (41-69mm), were available. For the first 1000 condom six-pack units that were sold, a total of 83 of the 95 unique sizes were purchased, including all 14 lengths and 12 widths, and both the smallest and largest condoms. Initial condom purchases were made by 572 individuals from 26 countries. Only 13.4% of consumer sales were in the ASTM's allowable range of sizes. These initial sales data suggest consumer interest in an expanded choice of condom sizes that fall outside the range currently allowable by national and international standards organisations.

Echinococcus-Host Interactions at Cellular and Molecular Levels.

PubMed

Brehm, K; Koziol, U

2017-01-01

The potentially lethal zoonotic diseases alveolar and cystic echinococcosis are caused by the metacestode larval stages of the tapeworms Echinococcus multilocularis and Echinococcus granulosus, respectively. In both cases, metacestode growth and proliferation occurs within the inner organs of mammalian hosts, which is associated with complex molecular host-parasite interactions that regulate nutrient uptake by the parasite as well as metacestode persistence and development. Using in vitro cultivation systems for parasite larvae, and informed by recently released, comprehensive genome and transcriptome data for both parasites, these molecular host-parasite interactions have been subject to significant research during recent years. In this review, we discuss progress in this field, with emphasis on parasite development and proliferation. We review host-parasite interaction mechanisms that occur early during an infection, when the invading oncosphere stage undergoes a metamorphosis towards the metacestode, and outline the decisive role of parasite stem cells during this process. We also discuss special features of metacestode morphology, and how this parasite stage takes up nutrients from the host, utilizing newly evolved or expanded gene families. We comprehensively review mechanisms of host-parasite cross-communication via evolutionarily conserved signalling systems and how the parasite signalling systems might be exploited for the development of novel chemotherapeutics. Finally, we point to an urgent need for the development of functional genomic techniques in this parasite, which will be imperative for hypothesis-driven analyses into Echinococcus stem cell biology, developmental mechanisms and immunomodulatory activities, which are all highly relevant for the development of anti-infective measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of two biologically distinct variants of Tomato spotted wilt virus

USDA-ARS?s Scientific Manuscript database

Significant economic losses result on a wide range of crops due to infection with Tomato spotted wilt virus (TSWV). In this study, two TSWV isolates, one from basil and a second from tomato, were established in a common plant host. Viral proteins were monitored over time, plant host ranges were comp...

Biology and host range of Heterapoderopsis bicallosicollis; a potential biological control agent for Chinese tallow Triadica sebifera

USDA-ARS?s Scientific Manuscript database

Chinese tallow, Triadica sebifera, is an invasive weed that infests natural and agricultural areas of the southeastern USA. A candidate for biological control of Chinese tallow has been studied under quarantine conditions. The biology and host range of a primitive leaf feeding beetle, Heterapoderops...